What do web.de bounce codes like c=hd and c=hi mean?

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.

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.

Marketer from Email Geeks suggests using the web.de postmaster site and contacting their team to resolve bounce issues, as well as inferring issues from other providers' bounce reasons. He believes their bounce page gives pointers to check specific items, and that the resources available may be easier to use than decoding header parameters.

Email marketer from Mailjet explains that high sending speed ('c=irlrm') can sometimes trigger rate limiting. They advise warming up IP addresses slowly and implementing proper sending volume controls to improve sender reputation.

Email marketer from SendPulse shares tips for improving your sending reputation. This includes ensuring proper authentication (SPF, DKIM, DMARC), avoiding spam traps, and consistently engaging with your audience.

Email marketer from Stack Overflow explains that web.de bounce codes are often specific to their system and not always well-documented. Suggests checking the web.de postmaster site for general information and contacting their support for specific code interpretations.

Marketer from Email Geeks explains the meaning of some web.de bounce codes: c=hd means the Date header is not to their liking, c=sp means the domain is blacklisted, and c=irlrm means sending too fast. He suspects 'h' in c=hi might stand for header.

Email marketer from EmailProviderReviews.com suggests that 'c=hd' might relate to header formatting issues, potentially with the Date header as seen by some senders. Also suggests it could potentially be a syntax error.

Email marketer from Reddit shares that they have seen `c=sp` indicating a Spamhaus listing. Recommends checking your domain and IP address against common blacklists if you receive this code.

Email marketer from MailingListAnswers explains that problems with the Date header ('c=hd') could be because the date is in the wrong format, or because the time is significantly different from the server's time.

Email marketer from DNSQueries suggests using tools such as theirs to check if your domain or IP is on a DNS Blocklist. This can help to verify 'c=sp' errors from web.de.

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.

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.

Expert from Email Geeks argues that the generic '554 Reject due to policy restrictions' message is unhelpful, as it doesn't specify the exact reason for rejection (technical, policy, recipient, etc.). He suggests that a helpful message would differentiate between header-based, domain-based, and IP-based rejections.

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.

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.

Documentation from IONOS Help Center explains that, in general, 5xx errors indicate a permanent delivery failure. While the specific 'c=' parameters used by Web.de are not documented, the article outlines general troubleshooting steps for email delivery problems.

Documentation from DKIM.org explains the importance of DomainKeys Identified Mail (DKIM) in verifying the sender and integrity of email messages. It explains how to set up DKIM records to improve deliverability.

Documentation from Spamhaus outlines that the 'c=sp' bounce code from web.de likely indicates a listing on a Spamhaus blocklist. It explains that Spamhaus lists IPs and domains involved in sending spam. Check to see if you are on the blocklist and follow instructions to get removed if appropriate.

Documentation from web.de Postmaster explains that their bounce messages contain codes that can help diagnose delivery issues. However, they do not provide a public, comprehensive list of all codes and their meanings.