gmail is modifying header(Message-ID) of incoming mails

Question

I sent a mail from my smtp server to gmail. The message-id that I got is: Message-ID: [email protected]> X-Google-Original-Message-ID:

Gmail appended extra parts in Message-id.

All I got on google that it can be an authentication issue.But source of mail shows: SPF:PASS

But DKIM is not present in the source. Do we require DKIM to be necessarily present in the mail's source?? What can I do to prevent header from being modified?

Answer 1

the msesage ID will be modified only if it does not obey RFC standard. so send mail with correct message id format