Bounce Classification Codes and Definitions
Email Bounce Classification is a powerful tool designed to help businesses monitor, classify, and resolve email delivery issues. By identifying the causes of bounced emails, it empowers users to optimize their email campaigns for better deliverability. This article will guide you through the key features, benefits, and steps to effectively use the Email Bounce Classification feature to ensure emails reach your recipients' inboxes.
Key Features and Benefits:
- Bounce Summary Overview: This feature provides detailed metrics on total permanent bounces, bounce rate, ESP/ISP blocks, and delivery rates, allowing you to assess email performance.
- Detailed Bounce Classification: Breaks down bounces by the email service provider (e.g., Gmail, Google Workspace, Apple), bounce category (Mailbox Full, DMARC, Sender Reputation, Internal Errors, etc.), and status/error codes, offering precise insights into delivery failures.
- ESP/ISP Block Tracking: Tracks blocks by email providers like Outlook or Google Workspace due to policy violations or spam-related issues, helping users take action with external troubleshooting links.
- Advanced Filters: Refine reports using filters like sending domain, email service provider, email type, or sending IP to drill down on specific issues.
- Actionable Troubleshooting: Provides direct links and guidance to resolve bounce issues like blacklist problems or misconfigured DNS records, improving email deliverability.
How to Use the Email Bounce Classification Feature:
Access the Dashboard:
Navigate to Settings > email services module within Mastermind. Look for the "Bounce Classification" section to access a comprehensive overview of your email bounces.
Review Metrics: Examine key metrics such as total permanent bounces, delivery rates, and bounce rates to understand your overall email performance.
Use Filters: Refine your report using advanced filters, such as selecting specific sending domains, email service providers, or error types to narrow down the exact causes of delivery issues.
Analyze Bounce Details: Delve into specific bounce classifications, reviewing error codes, status codes, and categories like DMARC failures or mailbox-related issues. Each category will include a definition and potential resolution tips.
Resolve Issues: Follow the actionable guidance provided with each bounce reason. For instance, if there is a DNS issue, the system will link you to resources for correcting SPF/DKIM/DMARC records or for resolving blacklist problems.
Monitor Blocks: Pay attention to ESP/ISP blocks by providers like Outlook or Gmail, and use the links provided to troubleshoot and unblock IPs or domains if necessary.
Below is a detailed breakdown of these codes, covering the causes of the issues and practical solutions to resolve them effectively. Use this guide to quickly identify and fix any delivery problems you may encounter.
Blocked
| Category | Code | Enhanced Code | Definition |
| Blocked | 554 | 5.2.3 | Your email was blocked because there's a policy or rule in place that's preventing the email from being delivered. This could be related to mailbox quotas, email size limits, or specific policies configured by the organization |
DMARC
The message failed DMARC authentication because the "From" header does not align with the domains verified by SPF/DKIM.
Resolution Tips:
- Ensure the "From" address aligns with the sending domain.
- Confirm that SPF and DKIM are properly set up for the sending domain.
| Category | Code | Enhanced Code | Definition |
| DMARC | 509 | 5.7.509 | The message was rejected by the recipient'semail provider because it did not pass the DMARC. Ensure that the "From" header domain matches or aligns with the SPF/DKIM-validated domains. |
| DMARC | 550 | 5.0.0 | The message was rejected by the recipient's email provider because it did not pass the DMARC. Ensure that the "From" header domain matches or aligns with the SPF/DKIM-validated domains. |
| DMARC | 550 | 5.7.20 | The message was rejected by the recipient's email provider because it did not pass the DMARC. Ensure that the "From" header domain matches or aligns with the SPF/DKIM-validated domains. |
| DMARC | 550 | 5.7.26 | The message was rejected by the recipient's email provider because it did not pass the DMARC. Ensure that the "From" header domain matches or aligns with the SPF/DKIM-validated domains. |
| DMARC | 550 | 5.7.5 | The message was rejected by the recipient's email provider because it did not pass the DMARC. Ensure that the "From" header domain matches or aligns with the SPF/DKIM-validated domains. |
| DMARC | 550 | 5.7.5 | The message was rejected by the recipient's email provider because it did not pass the DMARC. Ensure that the "From" header domain matches or aligns with the SPF/DKIM-validated domains. |
| DMARC | 550 | 5.7.509 | The message was rejected by the recipient's email provider because it did not pass the DMARC. Ensure that the "From" header domain matches or aligns with the SPF/DKIM-validated domains. |
| DMARC | 550 | 5.7.6 | The message was rejected by the recipient's email provider because it did not pass the DMARC. Ensure that the "From" header domain matches or aligns with the SPF/DKIM-validated domains. |
| DMARC | 550 | 5.7.8 | The message was rejected by the recipient's email provider because it did not pass the DMARC. Ensure that the "From" header domain matches or aligns with the SPF/DKIM-validated domains. |
| DMARC | 550 | 5.7.9 | The message was rejected by the recipient's email provider because it did not pass the DMARC. Ensure that the "From" header domain matches or aligns with the SPF/DKIM-validated domains. |
| DMARC | 550 | Missing | The message was rejected by the recipient's email provider because it did not pass the DMARC. Ensure that the "From" header domain matches or aligns with the SPF/DKIM-validated domains. |
| DMARC | 553 | - | The message was rejected by the recipient's email provider because it did not pass the DMARC. Ensure that the "From" header domain matches or aligns with the SPF/DKIM-validated domains. |
| DMARC | 554 | 5.0.0 | The message was rejected by the recipient's email provider because it did not pass the DMARC. Ensure that the "From" header domain matches or aligns with the SPF/DKIM-validated domains. |
| DMARC | 554 | 5.7.5 | The message was rejected by the recipient's email provider because it did not pass the DMARC. Ensure that the "From" header domain matches or aligns with the SPF/DKIM-validated domains. |
| DMARC | 555 | 5.7.5 | The message was rejected by the recipient's email provider because it did not pass the DMARC. Ensure that the "From" header domain matches or aligns with the SPF/DKIM-validated domains. |
Invalid Address
This means you tried to send a message to a non-existent email address. The recipient may have entered an incorrect address or made a typo.
Resolution Tips:
- Use Email Validation to verify email addresses before sending.
| Category | Code | Enhanced Code | Definition |
| Invalid address | 450 | 4.1.1 | The recipient's email address is invalid or does not exist. |
| Invalid address | 500 | 5.0.0 | The recipient's email address is invalid or does not exist. |
| Invalid address | 500 | 5.1.1 | The recipient's email address is invalid or does not exist. |
| Invalid address | 501 | 5.1.1 | The recipient's email address is invalid or does not exist. |
| Invalid address | 501 | 5.1.3 | The recipient's email address is invalid or does not exist. |
| Invalid address | 501 | 5.1.3 | The recipient's email address is invalid or does not exist. |
| Invalid address | 501 | 5.5.4 | The recipient's email address is invalid or does not exist. |
| Invalid address | 501 | 5.7.0 | The recipient's email address is invalid or does not exist. |
| Invalid address | 505 | - | The recipient's email address is invalid or does not exist. |
| Invalid address | 508 | 5.1.1 | The recipient's email address is invalid or does not exist. |
| Invalid address | 511 | 5.1.1 | The recipient's email address is invalid or does not exist. |
| Invalid address | 511 | - | The recipient's email address is invalid or does not exist. |
| Invalid address | 521 | 5.3.2 | The recipient's email address is invalid or does not exist. |
| Invalid address | 522 | 5.7.1 | The recipient's email address is invalid or does not exist. |
| Invalid address | 525 | 5.7.13 | The recipient's email address is invalid or does not exist. |
| Invalid address | 540 | 5.7.1 | The recipient's email address is invalid or does not exist. |
| Invalid address | 542 | - | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.0.0 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.0.0 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.0.1 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.0.350 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.1.0 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.1.1 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.1.1 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.1.1 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.1.10 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.1.10 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.1.181 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.1.2 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.1.2 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.1.351 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.1.351 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.1.6 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.2.1 | The email account that you tried to reach is inactive. |
| Invalid address | 550 | 5.2.1 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.2.14 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.2.5 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.3.0 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.3.2 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.3.2 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.4.310 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.4.312 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.4.350 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.4.355 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.5.0 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.5.1 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.5.2 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.7.0 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.7.1 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.7.100 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.7.13 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | 5.8.1 | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | - | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | - | The recipient's email address is either invalid or does not exist and is already on the bounce list. Please revalidate the email address and try again. |
| Invalid address | 550 | - | The recipient's email address is invalid or does not exist. |
| Invalid address | 550 | - | These errors are originating from the recipient's end due to a misconfiguration or an outage on their MX server. |
| Invalid address | 551 | 5.1.1 | The recipient's email address is invalid or does not exist. |
| Invalid address | 551 | 5.1.1 | The recipient's email address is invalid or does not exist. |
| Invalid address | 551 | - | The recipient's email address is invalid or does not exist. |
| Invalid address | 552 | 5.1.1 | The recipient's email address is invalid or does not exist. |
| Invalid address | 553 | 5.1.1 | The recipient's email address is invalid or does not exist. |
| Invalid address | 553 | 5.1.3 | The recipient's email address is invalid or does not exist. |
| Invalid address | 553 | 5.3.0 | The recipient's email address is invalid or does not exist. |
| Invalid address | 553 | 5.3.0 | The recipient's email address is invalid or does not exist. |
| Invalid address | 553 | 5.5.3 | The recipient's email address is invalid or does not exist. |
| Invalid address | 553 | 5.7.1 | The recipient's email address is invalid or does not exist. |
| Invalid address | 553 | 5.7.2 | The recipient's email address is invalid or does not exist. |
| Invalid address | 554 | 5.0.0 | The recipient's email address is invalid or does not exist. |
| Invalid address | 554 | 5.1.1 | The recipient's email address is invalid or does not exist. |
| Invalid address | 554 | 5.1.2 | The recipient's email address is invalid or does not exist. |
| Invalid address | 554 | 5.2.1 | The recipient's email address is invalid or does not exist. |
| Invalid address | 554 | 5.2.2 | The recipient's email address is invalid or does not exist. |
| Invalid address | 554 | 5.5.1 | The recipient's email address is invalid or does not exist. |
| Invalid address | 554 | 5.7.1 | The recipient's email address is invalid or does not exist. |
| Invalid address | 554 | 5.7.7 | The recipient's email address is invalid or does not exist. |
| Invalid address | 554 | - | The recipient's email address is invalid or does not exist. |
| Invalid address | 556 | 5.1.1 | The recipient's email address is invalid or does not exist. |
| Invalid address | 572 | - | The recipient's email address is invalid or does not exist. |
| Invalid address | 577 | 5.1.1 | The recipient's email address is invalid or does not exist. |
| Invalid address | 585 | 5.1.1 | The recipient's email address is invalid or does not exist. |
| Invalid address | 605 | - | The recipient's email address is already on the bounce list. Please revalidate the email address and try again. |
| Invalid address | 612 | - | These errors are originating from the recipient's end due to a misconfiguration or an outage on their MX server. |
Mailbox
This error suggests that the email address you attempted to send a message to does not have an active mailbox.
Resolution Tips:
- Verify email addresses using Email Validation before sending messages.
| Category | Code | Enhanced Code | Definition |
| Mailbox | 450 | 4.2.2 | The recipient's domain has no mailbox and does not accept mail. Please send it to a valid email address. |
| Mailbox | 452 | - | The recipient's domain has no mailbox and does not accept mail. Please send it to a valid email address. |
| Mailbox | 498 | - | The recipient's domain has no mailbox and does not accept mail. Please send it to a valid email address. |
| Mailbox | 511 | - | The recipient's domain has no mailbox and does not accept mail. Please send it to a valid email address. |
| Mailbox | 516 | 5.1.6 | The recipient's domain has no mailbox and does not accept mail. Please send it to a valid email address. |
| Mailbox | 522 | 5.2.2 | The recipient's domain has no mailbox and does not accept mail. Please send it to a valid email address. |
| Mailbox | 550 | 4.2.2 | The recipient's domain has no mailbox and does not accept mail. Please send it to a valid email address. |
| Mailbox | 550 | 5.0.350 | The recipient's domain has no mailbox and does not accept mail. Please send it to a valid email address. |
| Mailbox | 550 | 5.2.0 | The recipient's domain has no mailbox and does not accept mail. Please send it to a valid email address. |
| Mailbox | 550 | 5.2.2 | The recipient's domain has no mailbox and does not accept mail. Please send it to a valid email address. |
| Mailbox | 550 | 5.4.6 | The recipient's domain has no mailbox and does not accept mail. Please send it to a valid email address. |
| Mailbox | 550 | 5.5.0 | The recipient's domain has no mailbox and does not accept mail. Please send it to a valid email address. |
| Mailbox | 550 | 5.5.1 | The recipient's domain has no mailbox and does not accept mail. Please send it to a valid email address. |
| Mailbox | 552 | 5.1.1 | The recipient's domain has no mailbox and does not accept mail. Please send it to a valid email address. |
| Mailbox | 552 | 5.2.1 | The recipient's domain has no mailbox and does not accept mail. Please send it to a valid email address. |
| Mailbox | 552 | 5.5.2 | The recipient's domain has no mailbox and does not accept mail. Please send it to a valid email address. |
| Mailbox | 552 | - | The recipient's domain has no mailbox and does not accept mail. Please send it to a valid email address. |
| Mailbox | 553 | 5.3.1 | The recipient's domain has no mailbox and does not accept mail. Please send to valid email address. |
| Mailbox | 554 | 5.1.1 | The recipient's domain has no mailbox and does not accept mail. Please send to valid email address. |
Mailbox Full
A "Mailbox Full" bounce happens when the recipient's inbox has reached its storage capacity and is unable to receive new messages. This is typically a temporary issue, and emails can be delivered once the recipient clears space or increases their mailbox size.
| Category | Code | Enhanced Code | Definition |
| Mailbox Full | 452 | 4.1.1 | The recipient's mailbox is full and cannot accept new emails. |
| Mailbox Full | 452 | 4.2.2 | The recipient's mailbox is full and cannot accept new emails. |
| Mailbox Full | 550 | 5.2.2 | The recipient's mailbox is full and cannot accept new emails. |
| Mailbox Full | 552 | 5.2.2 | The recipient's mailbox is full and cannot accept new emails. |
| Mailbox Full | 552 | 5.2.2 | The recipient's mailbox is full and cannot accept new emails. |
| Mailbox Full | 552 | - | The recipient's mailbox is full and cannot accept new emails. |
Rate Limit
| Category | Code | Enhanced Code | Definition |
| Rate Limit | 221 | - | The recipient's server has denied your email. You’re sending mail to is getting too many emails too fast. Please contact the recipient using an alternative method. |
| Rate Limit | 550 | 4.2.1 | The recipient's server has denied your email. You’re sending mail to is getting too many emails too fast. Please contact the recipient using an alternative method. |
| Rate Limit | 550 | 5.2.1 | The recipient's server has denied your email. You’re sending mail to is getting too many emails too fast. Please contact the recipient using an alternative method. |
| Rate Limit | 550 | 5.2.122 | The recipient's server has denied your email. You’re sending mail to is getting too many emails too fast. Please contact the recipient using an alternative method. |
| Rate Limit | 554 | 5.2.121 | The recipient's server has denied your email. You’re sending mail to is getting too many emails too fast. Please contact the recipient using an alternative method. |
| Rate Limit | 554 | 5.2.122 | The recipient's server has denied your email. You’re sending mail to is getting too many emails too fast. Please contact the recipient using an alternative method. |
Recipient Error
| Category | Code | Enhanced Code | Definition |
| Recipient Error | 450 | - | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 502 | - | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 503 | - | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 510 | - | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 521 | 5.3.0 | Cloudflare’s email routing service indicates that the message encountered an issue related to Cloudflare’s email routing or processing. |
| Recipient Error | 530 | 5.3.0 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 530 | 5.7.0 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 530 | 5.7.1 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 530 | 5.7.1 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 530 | 5.7.57 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 530 | - | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 535 | - | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 541 | 5.4.1 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 4.4.0 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 4.4.2 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 4.4.7 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.1.3 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.1.9 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.3.5 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.4.103 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.4.108 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.4.142 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.4.300 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.4.315 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.4.316 | The mail server was unable to deliver the message after repeated attempts. The message eventually "expired" after exceeding the time limit set for retries. This usually happens when the recipient’s server refuses the connection or is unreachable for an extended period. |
| Recipient Error | 550 | 5.4.317 | The mail server was unable to deliver the message after repeated attempts. The message eventually "expired" after exceeding the time limit set for retries. This usually happens when the recipient’s server refuses the connection or is unreachable for an extended period. |
| Recipient Error | 550 | 5.4.4 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.4.7 | The email server has been trying to deliver the message for an extended period but has not been able to do so within the allowable time limit. The email has now been permanently rejected. |
| Recipient Error | 550 | 5.5.5 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.7.105 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.7.124 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.7.128 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.7.129 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.7.133 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.7.134 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.7.136 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.7.193 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.7.230 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.7.367 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.7.51 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.7.520 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.7.54 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.7.64 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.7.703 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.7.705 | The recipient's tenant in Microsoft 365 (or Office 365) has exceeded a specific limit or threshold, leading to the rejection of further email deliveries. This threshold could relate to various factors, such as the number of messages sent, the volume of inbound messages, or security thresholds based on suspicious activity. |
| Recipient Error | 550 | 5.7.900 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.7.902 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.7.929 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.7.987 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.7.999 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 550 | 5.8.2 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 551 | - | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 552 | 5.7.1 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 553 | 5.0.0 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 553 | 5.1.8 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 554 | 4.3.5 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 554 | 5.1.0 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 554 | 5.1.2 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 554 | 5.2.0 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 554 | 5.4.6 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 554 | 5.5.4 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 554 | 5.7.1 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 554 | 5.7.105 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 555 | 5.7.1 | The email platform you are trying to use is not supported for communication with Pixieset's systems. This error suggests that certain types of emails or configurations (e.g., unsupported email clients or formats) are not permitted by Pixieset's mail system. |
| Recipient Error | 556 | 5.7.1 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 556 | - | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 571 | - | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 577 | 5.7.7 | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 579 | - | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
| Recipient Error | 701 | - | The recipient's server has denied your email. Communication outside their domain has been restricted. Please contact the recipient using an alternative method. |
Rejection
| Category | Code | Enhanced Code | Definition |
| Rejection | 450 | 4.1.8 | These errors indicate that the sending domain does not have valid DNS records. To resolve these issues, please ensure that the sending domain is verified and that the necessary DNS records are added with your DNS provider. Follow these instructions to resolve this issue. |
| Rejection | 501 | 5.1.0 | These errors indicate that the sending domain does not have valid DNS records. To resolve these issues, please ensure that the sending domain is verified and that the necessary DNS records are added with your DNS provider. Follow these instructions to resolve this issue. |
| Rejection | 501 | 5.1.7 | These errors indicate that the sending domain does not have valid DNS records. To resolve these issues, please ensure that the sending domain is verified and that the necessary DNS records are added with your DNS provider. Follow these instructions to resolve this issue. |
| Rejection | 501 | 5.1.8 | These errors indicate that the sending domain does not have valid DNS records. To resolve these issues, please ensure that the sending domain is verified and that the necessary DNS records are added with your DNS provider. Follow these instructions to resolve this issue. |
| Rejection | 501 | 5.2.0 | These errors indicate that the sending domain does not have valid DNS records. To resolve these issues, please ensure that the sending domain is verified and that the necessary DNS records are added with your DNS provider. Follow these instructions to resolve this issue. |
| Rejection | 501 | NA | These errors indicate that the sending domain does not have valid DNS records. To resolve these issues, please ensure that the sending domain is verified and that the necessary DNS records are added with your DNS provider. Follow these instructions to resolve this issue. |
| Rejection | 533 | 5.7.1 | These errors indicate that the sending domain does not have valid DNS records. To resolve these issues, please ensure that the sending domain is verified and that the necessary DNS records are added with your DNS provider. Follow these instructions to resolve this issue. |
| Rejection | 550 | 5.1.0 | These errors indicate that the sending domain does not have valid DNS records. To resolve these issues, please ensure that the sending domain is verified and that the necessary DNS records are added with your DNS provider. Follow these instructions to resolve this issue. |
| Rejection | 550 | 5.1.0 | These errors indicate that the sending domain does not have valid DNS records. To resolve these issues, please ensure that the sending domain is verified and that the necessary DNS records are added with your DNS provider. Follow these instructions to resolve this issue. |
| Rejection | 550 | 5.1.7 | These errors indicate that the sending domain does not have valid DNS records. To resolve these issues, please ensure that the sending domain is verified and that the necessary DNS records are added with your DNS provider. Follow these instructions to resolve this issue. |
| Rejection | 550 | 5.1.8 | These errors indicate that the sending domain does not have valid DNS records. To resolve these issues, please ensure that the sending domain is verified and that the necessary DNS records are added with your DNS provider. Follow these instructions to resolve this issue. |
| Rejection | 550 | 5.2.3 | The email message is too large for the recipient, exceeding their size limit. |
| Rejection | 550 | 5.4.0 | The email has been bounced back due to the email message exceeding the maximum number of allowed hops (transfers between mail servers). This usually happens when there is a mail loop or when the message has passed through too many servers. |
| Rejection | 550 | 5.4.12 | The email has been bounced back due to the email message exceeding the maximum number of allowed hops (transfers between mail servers). This usually happens when there is a mail loop or when the message has passed through too many servers. |
| Rejection | 550 | 5.4.14 | The email has been bounced back due to the email message exceeding the maximum number of allowed hops (transfers between mail servers). This usually happens when there is a mail loop or when the message has passed through too many servers. |
| Rejection | 550 | 5.4.6 | Your email was blocked by the recipient's email provider because a mail loop was detected. |
| Rejection | 550 | 5.5.2 | These errors indicate that the sending domain does not have valid DNS records. To resolve these issues, please ensure that the sending domain is verified and that the necessary DNS records are added with your DNS provider. Follow these instructions to resolve this issue. |
| Rejection | 550 | 5.7.13 | These errors indicate that the sending domain does not have valid DNS records. To resolve these issues, please ensure that the sending domain is verified and that the necessary DNS records are added with your DNS provider. Follow these instructions to resolve this issue. |
| Rejection | 550 | 5.7.21 | These errors indicate that the sending domain does not have valid DNS records. To resolve these issues, please ensure that the sending domain is verified and that the necessary DNS records are added with your DNS provider. Follow these instructions to resolve this issue. |
| Rejection | 550 | 5.7.23 | These errors indicate that the sending domain does not have valid DNS records. To resolve these issues, please ensure that the sending domain is verified and that the necessary DNS records are added with your DNS provider. Follow these instructions to resolve this issue. |
| Rejection | 550 | 5.7.23 | These errors indicate that the sending domain does not have valid DNS records. To resolve these issues, please ensure that the sending domain is verified and that the necessary DNS records are added with your DNS provider. Follow these instructions to resolve this issue. |
| Rejection | 550 | 5.7.23 | These errors indicate that the sending domain does not have valid DNS records. To resolve these issues, please ensure that the sending domain is verified and that the necessary DNS records are added with your DNS provider. Follow these instructions to resolve this issue. |
| Rejection | 550 | 5.7.24 | These errors indicate that the sending domain does not have valid DNS records. To resolve these issues, please ensure that the sending domain is verified and that the necessary DNS records are added with your DNS provider. Follow these instructions to resolve this issue. |
| Rejection | 550 | 5.7.24 | These errors indicate that the sending domain does not have valid DNS records. To resolve these issues, please ensure that the sending domain is verified and that the necessary DNS records are added with your DNS provider. Follow these instructions to resolve this issue. |
| Rejection | 550 | 5.7.26 | These errors indicate that the sending domain does not have valid DNS records. To resolve these issues, please ensure that the sending domain is verified and that the necessary DNS records are added with your DNS provider. Follow these instructions to resolve this issue. |
| Rejection | 550 | 5.7.27 | These errors indicate that the sending domain does not have valid DNS records. To resolve these issues, please ensure that the sending domain is verified and that the necessary DNS records are added with your DNS provider. Follow these instructions to resolve this issue. |
| Rejection | 550 | 5.7.368 | These errors indicate that the sending domain does not have valid DNS records. To resolve these issues, please ensure that the sending domain is verified and that the necessary DNS records are added with your DNS provider. Follow these instructions to resolve this issue. |
| Rejection | 550 | 5.7.57 | These errors indicate that the sending domain does not have valid DNS records. To resolve these issues, please ensure that the sending domain is verified and that the necessary DNS records are added with your DNS provider. Follow these instructions to resolve this issue. |
| Rejection | 553 | 5.1.8 | These errors indicate that the sending domain does not have valid DNS records. To resolve these issues, please ensure that the sending domain is verified and that the necessary DNS records are added with your DNS provider. Follow these instructions to resolve this issue. |
| Rejection | 554 | 5.1.8 | These errors indicate that the sending domain does not have valid DNS records. To resolve these issues, please ensure that the sending domain is verified and that the necessary DNS records are added with your DNS provider. Follow these instructions to resolve this issue. |
| Rejection | 554 | NA | Possible reasons: the right of the @ in the MAIL FROM does not appear to be valid or poor reputation of a sending domain. |
Sender Reputation
How to Fix: Email Blocked Due to Potential Spam or Malicious Activity
Check IP and Domain BlacklistsUtilize tools like a Blacklist Checker to determine if your IP or domain has been flagged.
If listed, follow the delisting process provided by the respective Blacklist Service.
- Verify DNS ConfigurationEnsure the following DNS records are properly configured for your domain:
- SPF (Sender Policy Framework)
- DKIM (DomainKeys Identified Mail)
DMARC (Domain-based Message Authentication, Reporting, and Conformance)
Use tools like MXToolbox to verify the SPF, DKIM, and DMARC records are valid.
- Track and Improve Email Reputation
- Microsoft SNDS: Check your IP reputation with Microsoft services like Outlook and Hotmail.
- Google Postmaster Tools: Monitor how Gmail handles your emails and analyze deliverability metrics.
- Send Emails in Smaller Batches to Build TrustTo avoid issues, gradually increase the volume of emails sent from new or inactive IPs/domains. Start with smaller batches to establish a positive reputation.
Maintain a Clean Email ListRegularly remove inactive or invalid email addresses to minimize bounces.
Utilize email validation tools to ensure your list is clean before launching campaigns.
Monitor spam complaints and promptly remove problematic contacts.
- Follow Best Practices for Email Content
- Avoid using spam-like language in subject lines (e.g., "Congratulations!!!" or "Act Now!").
- Balance text and images within your email to avoid sending image-only messages.
- Ensure all links in your email are secure and not blacklisted.
- Always include an unsubscribe link in your marketing emails to comply with anti-spam regulations.
FAQs for Email Bounce Classification
1. What is Email Bounce Classification?
Email Bounce Classification is a feature that identifies and categorizes bounced emails based on their causes, allowing users to analyze email delivery issues and optimize their campaigns to reach more recipients effectively.
2. How can I access the Bounce Classification feature?
Go to Settings > Email Services in the Mastermind platform, and locate the "Bounce Classification" section. This will provide an overview of your email bounces along with insights for troubleshooting.
3. What are the main categories of email bounces?
Common categories include:
- Mailbox Full: The recipient’s mailbox is full.
- DMARC/Authentication Issues: Failed authentication due to incorrect DMARC, SPF, or DKIM settings.
- Sender Reputation: Low sender reputation, causing emails to be flagged as spam.
- Internal Errors: Issues on the email provider’s end, leading to delivery failures.
4. How can I filter bounces to investigate specific issues?
Use advanced filters in the Bounce Classification dashboard to narrow down results by:
- Sending domain
- Email service provider (ESP/ISP)
Email type or sending IP
This helps isolate specific issues based on the chosen parameters.
5. What insights does the Bounce Summary provide?
The Bounce Summary gives you a quick view of total permanent bounces, bounce rates, ESP/ISP blocks, and delivery rates, enabling you to assess the performance of your email campaigns at a glance.
6. How do I resolve issues shown in the bounce details?
Each bounce type comes with actionable guidance:
- For DNS Issues: Access links to update SPF/DKIM/DMARC records.
- For Blacklist Problems: Get resources to remove your IP/domain from blacklists.
- For ISP Blocks: Follow external troubleshooting links to contact providers like Outlook or Gmail.