[BlueOnyx:26736] Re: DKIM

[Richard Sidlin]

Hi Michael

> Hi Richard,
> https://mxtoolbox.com/Public/Tools/EmailHeaders.aspx?huid=2cd2b490-
> c533-4f46-9135-10335cf9ff51
> 
> The error message from MX-Toolbox is:
> 
> DKIM Signature Body Hash Verified 	Body Hash Did Not Verify
> 
> The DKIM stuff seems to be properly set up on your server and when I check
> the validity of the DKIM it actually looks good.
> 
> The most common reason for this error is that the email content (the
> body) was altered after the DKIM signature was applied. DKIM signatures are
> very sensitive to changes in the email. Even a minor alteration like changing a
> character or adding a space can cause the body hash to not verify. This could
> happen due to forwarding, auto-responders, or any intermediate servers that
> might modify the email content.
> 
> Sometimes, during the transit of the email from the sender to the recipient,
> the email might go through various systems or services that could alter its
> content or format. This includes MTAs (Mail Transfer
> Agents) or email gateways that might modify the email, causing the DKIM
> signature to not match.
> 
> Ensure that the email is not being altered in transit. If the email goes through
> any intermediate systems, check to see if they are modifying the email
> content.
> 
> Try sending a very simple email (with minimal formatting and content) to see if
> the issue persists. This can help determine if the problem is with the email
> content or with the DKIM setup itself.
> 
> For example:
> 
> Your Email also has ARC related headers. If these were applied AFTER the email
> has been signed by DKIM, then that might cause this issue. You'd usually first
> apply ARC headers and then let the email be signed by DKIM.
> 
> It could also be that in the process of forwarding and/or SPAM-Filtering
> changes were made to the message body. Like when the forwarder (if it wasn't
> a BlueOnyx forwarder for example) added a custom footer to the email body.
> 
Yes, the firewall was adding a "Scanned by ..." message to the email. Disabled it and now passes. Thanks for the advice.

Richard