I set up IRedMail on an AWS server, so the mail stack looks something like this:
- Mail sent through Amazon SES
I'm trying to forward emails to Gmail using the Managesieve plugin in Roundcube. Forwarded emails get returned with the message
554 Transaction failed: Duplicate header 'DKIM-Signature'.
if sent from another account on that domain, and
554 Message rejected: Email address is not verified. (in reply to end of DATA command)
if sent from an external account. Adding the account as a "Send From" account in Gmail did not make it lenient enough to accept the forwarded messages. How could I go about debugging this?