On 12 Oct 2020, at 02:51, webadmin@exalt.com.au wrote:

I created a client library to send emails for a webapp.

When the client library makes a connection to the SMTP server, and then do NOT add Message-Id header, Message-ID (with a capital D) header is added, and the SMTP server adds a incorrect DKIM-Signature record 'h' part, invalidating the generated DKIM signature value.

This I s not a dovecot issue I don't think, this is a configuration issue with your MTA (exit, postfix, sendmail, et al).

The work around is to add to the message a Message-Id with a little ‘d’ header. Then the SMTP server processes the email with the correct DKIM-Signature, correct DKIM ‘h’ part and does not add a Message-ID header.

This seems very very wrong as the headers in mail messages are not case sensitive.

Also, I do not think dovecot adds message-id headers at all, and dovecot would not be involved in sending mail.

-- Ah we're lonely, we're romantic / and the cider's laced with acid / and the Holy Spirit's crying, Where's the beef? / And the moon is swimming naked / and the summer night is fragrant / with a mighty expectation of relief