How do I fix DKIM failing body hash verification?

Email marketer from Mailhardener responds that if the DKIM signature fails due to body hash mismatch, verify if the sender is correctly signing the email using the correct DKIM key. It also advises to check for possible tampering during transit.

Email marketer from Super User responds that the 'body hash did not verify' error indicates the message body changed after DKIM signing. This can be due to modifications by mail servers or email clients. Examine the message headers to track the path and identify any potential modification points.

Email marketer from MXToolbox shares to ensure that your sending server isn't configured to automatically add signatures, disclaimers or footers after DKIM signing. These additions will change the message body and invalidate the DKIM signature.

Email marketer from Reddit suggests that ensuring consistent line endings (using LF instead of CRLF) and character encoding (UTF-8) can help prevent DKIM body hash failures. Also, check for any server-side scripts that might be adding footers or altering the message body.

Email marketer from cPanel Forum explains that if the DKIM body hash fails, it is essential to ensure that the signing process occurs *after* any automated modifications, such as adding footers. Moving the signing process later can often resolve the issue.

Email marketer from EmailOnAcid explains that a common cause for body hash verification failure is when the email content is altered after DKIM signing, either by the sending server, an intermediary server, or the receiving server. Implement monitoring to detect such alterations.

Email marketer from Stack Overflow explains that a DKIM body hash failure can happen if your mail server is modifying the message after it's signed. They suggest ensuring that no processes are altering the message content, especially line endings or character encodings.

Expert from Email Geeks explains that if DKIM body hash verification is failing in both Gmail and Outlook, the signer is likely broken or the message is being modified in transit. Regenerating the public/private key pair is the first suggestion.

Expert from Email Geeks shares that Google is a good benchmark for checking email authentication due to its robust system and easy result retrieval. Problems at Microsoft should be verified against Google first.

Expert from Email Geeks explains that if DKIM body hash verification is failing only in Outlook, it's likely a text encoding issue in the message, causing Microsoft's system to have problems with the body hash. This can be fixed by changing the encoding of the outbound MTA.

Expert from SpamResource.com explains that DKIM failures, including body hash mismatches, often occur when the email content is modified after the DKIM signature is applied. This can be due to auto-responders, forwarding, or list servers adding footers or disclaimers. Ensure that your signing process occurs after all content modifications.

Expert from Word to the Wise explains that one of the primary reasons for DKIM failing to verify is content modification, which can affect the body hash. This may be caused by mailing list software, corporate disclaimers, or even the receiving mail server modifying the email. They suggest examining the email headers to determine where the content was changed.

Documentation from RFC 6376 specifies that DKIM signatures are sensitive to even minor changes in the message body. Any modification, including whitespace changes, character encoding differences, or the addition of content, will cause the body hash verification to fail.

Documentation from OpenDKIM Project suggests that if a DKIM signature verification fails due to body hash mismatch, ensure that the message content hasn't been modified by intermediate servers or mail clients. Check for any transformations like adding footers, changing character encoding, or altering line breaks.

Documentation from dkim-milter.org explains that a 'body hash did not verify' error typically indicates that the message body was altered in transit after signing. This could be due to line wrapping by mail transfer agents (MTAs), character set conversion, or the addition of disclaimers.