Summary
Web.de uses specific bounce codes within their error messages to indicate the reason for email delivery failure, such as 'c=hd' (likely a Date header issue), 'c=sp' (probable Spamhaus listing), and 'c=irlrm' (potential rate limiting due to sending speed). However, Web.de does not provide a comprehensive, public list of all codes. This means troubleshooting often requires experimentation and can be difficult. Contacting web.de support might be helpful, although some users have found it unhelpful. Experts recommend monitoring sender reputation, following RFC 5322 for the Date header, and employing proper authentication (DKIM, DMARC) to improve deliverability.
Key findings
- Code Meanings: Some web.de bounce codes have been partially deciphered: c=hd (likely Date header issue), c=sp (probable Spamhaus listing), c=irlrm (potential rate limiting).
- Undocumented Codes: Web.de does not publish a complete list of their bounce codes and their meanings.
- Generic Rejection Messages: The error messages from web.de are often generic and unhelpful, as they don't specify a reason.
- Reputation Monitoring: Proactive monitoring of sender reputation is crucial for identifying and addressing deliverability problems with web.de.
- Third-Party Lists: Being on a third-party blocklist will negatively affect deliverability. If you receive c=sp, you need to check your domain/ip is not on a blocklist.
Key considerations
- Experimentation Needed: Troubleshooting web.de bounce codes often requires experimentation and analysis of your email configuration.
- Date Header: If getting 'c=hd' check your email's Date header conforms to RFC 5322.
- Contact Postmaster: Contact web.de's postmaster support to get clarifications about specific bounces affecting your mail flow.
- Proper authentication: Implement SPF, DKIM and DMARC.
- Reduce Sending Speeds: To avoid 'irlrm' errors warm up IPs slowly.
What email marketers say
11 marketer opinions
Web.de uses specific bounce codes within their error messages (e.g., c=hd, c=hi, c=sp, c=irlrm) to indicate the reason for email delivery failure. While web.de's postmaster site is recommended for checking general issues and contacting support, the specific codes are not comprehensively documented. Some codes have been deciphered by email marketers, with 'c=hd' possibly relating to Date header formatting issues, 'c=sp' indicating a Spamhaus listing, and 'c=irlrm' suggesting excessive sending speed. The 'c=' parameters are likely internal tracking codes for web.de support and can be difficult to decode definitively, meaning experimentation is needed to fix the issues. If 'c=sp' is present, checking your domain and IP against blacklists is crucial.
Key opinions
- Code Meanings: Some web.de bounce codes have been partially deciphered: c=hd (Date header issue), c=sp (Spamhaus listing), c=irlrm (excessive sending speed).
- Lack of Documentation: Web.de does not provide a comprehensive public list of all bounce codes and their meanings.
- Support Limitations: Contacting web.de support or using the postmaster site may provide limited or generic assistance.
- Header Issues: 'c=hd' may mean date is in wrong format, or because the time is significantly different from the server's time, or there is a syntax error.
- Blacklist Checking: If you receive c=sp, you need to check your domain/ip is not on a blocklist. Check authentication (SPF, DKIM, DMARC).
Key considerations
- Experimentation Needed: Due to the lack of official documentation, troubleshooting web.de bounce codes often requires experimentation and analysis of your email configuration.
- Monitor Reputation: Proactively monitor your sender reputation and bounce rates to identify and address deliverability issues promptly.
- Contact Web.de: Despite limitations, reaching out to web.de's postmaster support may provide some insights into specific bounce issues.
- Examine Headers: Be careful to ensure you are following proper header formatting, especially the date.
- Check Sending Limits: Reduce sending speeds to resolve 'irlrm' and warm up IPs slowly.
Marketer view
Email marketer from Email Marketing Forum user advises that the 'c=' parameters are likely internal tracking codes for web.de's support team. Unless web.de publishes a key, they are difficult to decode definitively.
13 Jan 2025 - Email Marketing Forum
Marketer view
Marketer from Email Geeks shares their experience that web.de support was unhelpful, and that the bounce link contains specific codes that need to be researched independently, which is bad product design. Also states that web.de can be more strict than other ESPs, but is experimenting to find the specific cause of the issue.
17 Jan 2022 - Email Geeks
What the experts say
3 expert opinions
Experts agree that web.de employs proprietary and often undocumented bounce codes. The generic nature of some error messages, such as '554 Reject due to policy restrictions,' offers little actionable information. Consequently, diagnosing delivery issues requires proactively monitoring sender reputation, analyzing bounce rates, and, despite potential limitations, contacting web.de's postmaster support for clarification.
Key opinions
- Proprietary Codes: Web.de utilizes bounce codes that are not publicly documented in full.
- Generic Messages: Some web.de rejection messages are generic and lack specific details about the cause of the rejection.
- Reputation Monitoring: Proactive monitoring of sender reputation is crucial for identifying and addressing deliverability problems with web.de.
Key considerations
- Contact Postmaster: Contact web.de's postmaster support to get clarifications about the effect on mail flow.
- Monitor Bounce Rates: Closely examine web.de bounce rates as part of your reputation management.
- Feedback Loops: Implement tools and feedback loops to diagnose and address deliverability issues effectively.
Expert view
Expert from Word to the Wise highlights the importance of proactively monitoring your sender reputation, which includes understanding bounce messages (though it doesn't provide specific web.de code interpretations). They emphasize tools and feedback loops for ISPs like web.de to diagnose and address deliverability issues effectively.
21 Feb 2023 - Word to the Wise
Expert view
Expert from Spamresource.com explains that web.de, like many ISPs, uses proprietary bounce codes that are not publicly documented in full. They suggest monitoring bounce rates and contacting web.de's postmaster support for clarification on specific bounce codes affecting your mail flow.
28 May 2022 - Spamresource.com
What the documentation says
6 technical articles
Documentation confirms that Web.de uses bounce codes to help diagnose delivery issues, but a comprehensive list is not publicly available. General 5xx errors indicate permanent failures. If the bounce code includes 'c=sp', it likely signifies a Spamhaus blocklist. A properly formatted Date header (RFC 5322) is important, and DKIM and DMARC are vital for verifying senders and improving deliverability.
Key findings
- Undocumented Codes: Web.de does not publish a complete list of their bounce codes.
- 5xx Errors: 5xx errors generally indicate permanent email delivery failures.
- Spamhaus Listing: The 'c=sp' bounce code likely means a listing on a Spamhaus blocklist.
- Date Header Format: RFC 5322 defines the correct format for the Date header.
- DKIM Importance: DKIM is important for verifying the sender and integrity of email messages.
- DMARC Function: DMARC prevents email spoofing and phishing.
Key considerations
- Check Spamhaus: If you get a 'c=sp' error, check if you are on a Spamhaus blocklist and follow removal instructions.
- Date Header Format: Ensure your Date header conforms to RFC 5322.
- Implement DKIM: Set up DKIM records to improve deliverability.
- Setup DMARC: Configure DMARC to prevent spoofing and improve email security.
Technical article
Documentation from DMARC.org outlines the function of DMARC (Domain-based Message Authentication, Reporting & Conformance) and its role in preventing email spoofing and phishing. Also, explains how to set up DMARC records and interpret the results to improve email security and deliverability.
7 May 2024 - DMARC.org
Technical article
Documentation from RFC Editor specifies the required format for the Date header in email messages. It explains the format, which includes the day, date, time, and time zone.
13 Aug 2021 - RFC Editor
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