Hi all, I now have authenticated submission on port 587 working regardless of whether the connecting host has a PTR record.
Here are the steps taken: 1) Built OpenSMTPd and associated software from ports on FreeBSD 13. 2) Wiped my iPhone and configured my mail account again. This log excerpt is from my phone this morning: smtp connected address=22.214.171.124 host=<unknown> Aug 15 08:46:41 [redacted] smtp tls ciphers=TLSv1.3:TLS_AES_256_GCM_SHA384:256 Aug 15 08:46:42 [redacted] smtpd [redacted] smtp authentication user=pete result=ok I'm not really sure if I have configured anything different by using ports (I used 'pkg install' previously on another server) but all is good. I have a suspicion that it was actually my phone which was causing the issue. Here are my notes which I hope will help. https://valar.uk.net/smtpd-valar.conf Pete.
Description: S/MIME cryptographic signature