Hello list, I am relatively confident that the topic below has already been discussed somewhere, but I was not able to find anything in this list's archives nor on the internet at large and I have not been able to solve the issue: Microsoft's outlook.com seems to silently discard emails that I send from two different SMTP servers:
(A) self-operated Postfix on a Digital Ocean droplet, has been in operation for a few years, no complaints or problems, low traffic (average less than 500 emails/day). SPF/DKIM/DMARC/PTR anything that I can think of is properly set up and scores 10/10 on https://www.mail-tester.com/ Logs: Jan 4 23:43:13 mx postfix/smtp[29713]: Host offered STARTTLS: [hotmail-ca.olc.protection.outlook.com] Jan 4 23:43:13 mx postfix/smtp[29713]: ABD28C03F9: to=<xxxxxxxxxxx...@hotmail.ca>, relay=hotmail-ca.olc.protection.outlook.com[104.47.54.33]:25, delay=1.2, delays=0.34/0.01/0.24/0.6, dsn=2.6.0, status=sent (250 2.6.0 <6ea1a86e-bc93-3f7e-81ef-9a10d3a84...@moneylaw.ca> [InternalId=3461743652204, Hostname=DM3NAM06HT901.Eop-nam06.prod.protection.outlook.com] 138931 bytes in 0.359, 377.884 KB/sec Queued mail for delivery) (B) my university's alumni email, operated by Google. I have no logs for it, but I am confident Google's servers are OK. In both cases I am given the impression that my email has been "queued for delivery" or otherwise accepted, BUT... (1) Recipient: a person that I never corresponded with before: does not receive anything, neither from (A) nor from (B) (2) Recipient: an outlook.com mailbox that I keep for test purposes: does not receive from (A) nor from (B), but does receive replies from (A) in response to an email that was first sent from outlook.com to (A) (3) Recipient: a person in a large organization that has switched about a year ago to office365 and with whom I have weekly email exchanges: receives from (A) and (B), no problem. If there was at least an indication of rejection, I could try to contact my correspondents otherwise. Instead, Microsoft tells my server that everything is OK and then drops the ball, leaving sender and recipient in the dark. In my view, Microsoft's conduct is unacceptable. If it does not deliver an email, it should at least notify the sender SMTP? Have other SMTP operators been confronted with this? And what have you done about it, if anything? Is there anything I can do to improve my self-operated SMTP server to increase likelihood of delivery through Microsoft? Has anybody been able to engage with Microsoft on the subject? How, through what point of contact, and to what result? Thanks, Yuval Levy, JD, MBA, CFA Ontario-licensed lawyer
