I ran face first into that a few weeks ago. An internal app was using Mailgun to send out occasional info and alerts, and they suddenly stopped arriving.
I was kinda surprised it wasn't an existing feature to clean up bad headers before passing messages on for delivery. For bizarre old equipment (i.e. ancient copiers) we have a simple SMTP proxy that cleans everything up before sending messages on. We wanted to ditch it and just go straight through Mailgun, but that'll have to wait I guess. -A On Thu, May 1, 2025 at 9:09 AM Yiorgos [George] Adamopoulos via mailop < [email protected]> wrote: > We have a client of theirs sending to us password recovery emails without > proper MessageID. As a result, Google Workspace drops the email message, > thus password recovery is impossible. > > Apr 30, 2025, 12:54:10 PM Received from an SMTP client with IP address: > 69.72.33.38 (TLS enabled) > Apr 30, 2025, 12:54:10 PM Bounced > 550-5.7.1 [209.85.220.69] Messages missing a valid Message-ID header are > not > 550-5.7.1 accepted. For more information, go to > 550-5.7.1 https://support.google.com/mail/?p=RfcMessageNonCompliant and > review > 550 5.7.1 RFC 5322 specifications. > d9443c01a7336-22db4c039a8sor86173515ad.0 - gsmtp > Apr 30, 2025, 12:54:10 PM Received from an SMTP server with IP address: > 209.85.220.69 (TLS enabled) > 550-5.7.1 [209.85.220.69] Messages missing a valid Message-ID header are > not > 550-5.7.1 accepted. For more information, go to > 550-5.7.1 https://support.google.com/mail/?p=RfcMessageNonCompliant and > review > 550 5.7.1 RFC 5322 specifications. > Apr 30, 2025, 12:54:10 PM Bounced > If anyone can point me to a contact person to describe this weirdness, > that would be much appreciated. > > -- > > keep raising the bar || https://gr.linkedin.com/yiorgos > _______________________________________________ > mailop mailing list > [email protected] > https://list.mailop.org/listinfo/mailop >
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