On Mon, 4 Feb 2019 21:29:19 -0800 Richard Johnson <[email protected]> wrote: > What seems strange is that MOST of the time messages go through just > fine, but ever now-and-then I'll get this failure notice.
Off the top of my head 1) they've a round-robin cluster of MXers in which some are configured differently, or 2) they've transient DNS lookup failures. FWIW I do have smtpd_helo_restrictions = reject_unknown_helo_hostname smtpd_sender_restrictions = reject_unknown_sender_domain on our servers because vast majority of our legitimate senders come from .edu addersses (or their home ISPs) while b0rk3d DNS is a common feature of spam. -- Dmitri Maziuk <[email protected]> ------------------------------------------------------ Mailman-Users mailing list [email protected] https://mail.python.org/mailman/listinfo/mailman-users Mailman FAQ: http://wiki.list.org/x/AgA3 Security Policy: http://wiki.list.org/x/QIA9 Searchable Archives: http://www.mail-archive.com/mailman-users%40python.org/ Unsubscribe: https://mail.python.org/mailman/options/mailman-users/archive%40jab.org
