On 2022-03-10 at 15:28 -0500, John Levine via mailop wrote: > If you really want to stop mail loops, use a Delivered-To header like > qmail, Postfix, and Courier do: > > https://datatracker.ietf.org/doc/draft-duklev-deliveredto/
You still need to stop at *some* hop-count. This approach stops delivery loops, but not all loops involve a delivery. It's not a common occurrence, sure but perhaps 1-2 times a year I do see one such loop from using email addresses that should have been working. E.g. your email arrives to the on-premises MTA, which not finding a local user passes it to Office 365 who doesn't have that either so it is sent again to on-pre Regards _______________________________________________ mailop mailing list mailop@mailop.org https://list.mailop.org/listinfo/mailop
