Wietse Venema: > The exact message, incluing the name 'alph765' of the cluster with > broken reverse DNS: > https://forums.att.com/conversations/att-internet-email-security/prodigynet-reverse-dns-lookup-is-broken/5f07b53ac17a063d9bfecdb8 > > It affects multiple domains hosted at AT&T: > https://community.spiceworks.com/topic/2093608-reverse-dns-record-for-email-rejected-by-sbcglobal > https://www.netsolinc.com/prodigy-email-issues/ > > This is what I did when GMAIL was randomly bouncing mail because > of some bogus DNS error: > > /etc/postfix/main.cf: > transport_maps = hash:/etc/postfix/transport > [... details omitted...]
That was years ago. A more targeted approach is to use smtp_delivery_status_filter with a regexp that targets that exact error message, and that changes a 'hard' reject into a soft one. For inspiration to turn hard into soft rejects, see examples at http://www.postfixlorg/postconf.5.html#default_delivery_status_filter Wietse
