On 2021-01-23 at 23:56 +0100, Ángel wrote: > If any, you would want to define some kind of rejection message that > provided the equivalent of a "HTTP 301" so that the MTA itself could > redirect it to the right mailbox.
And just minutes after sending this, I notice that reply code 551 is precisely for that. Still, the rest of security considerations apply. Nonetheless, I'm sure SendGrid could have the initial proofpoint MTA forward ab...@sendgrid.com to a separate domain, thus avoiding Google filters and the need of having the MTA a custom code. Best regards _______________________________________________ mailop mailing list mailop@mailop.org https://list.mailop.org/listinfo/mailop
