Can't send email to an external domain via relay.free-online.net

[#1]

Since some time last night, I can't send emails to external domains.

emails to free-online addresses are delivered OK, but emails to a gmx or gmail address are not delivered.

The log show that they were accepted for delivery, but they never arrive:

Jan  7 09:25:50 andrew postfix/pickup[2801249]: 3A972E079D: uid=1000 from=<XXXXXXXX@XXXXXXXX>
Jan  7 09:25:50 andrew postfix/cleanup[2808101]: 3A972E079D: message-id=<20240107092550.3A972E079D@andrew.lan>
Jan  7 09:25:50 andrew postfix/qmgr[2801248]: 3A972E079D: from=<XXXXXXXX@XXXXXXXX>, size=353, nrcpt=1 (queue active)
Jan  7 09:25:51 andrew postfix/smtp[2808104]: 3A972E079D: to=<XXXXXXXX@XXXXXXXX>, relay=relay.free-online.net[212.159.9.105]:25, delay=1.7, delays=0.1/0.08/1.2/0.25, dsn=2.0.0, status=sent (250 MPPir4kovlpMnMPPjr6Dia mail accepted for delivery)
Jan  7 09:25:51 andrew postfix/qmgr[2801248]: 3A972E079D: removed

[#2]

@andrewww you might want to read through this thread https://community.plus.net/t5/Email/Cannot-send-to-gmail-addresses/m-p/1934005#M44287 and see which category you're in

[#3]

@MisterW

After further investigation, it appears to be only emails sent from command-line scripts. I've done some testing with my email client, and emails sent to a gmx domain work OK.

I note that the link you included refers to issues arising several months ago. Its odd that the problem only started late last night/early this morning and I've not changed or updated anything. Anyway, since I'm sending via a legacy Free-Online domain, that link suggests there's no fix, if that is the problem.

I'll do some more digging into the command-line email setup.

[#4 · Accepted solution]

@andrewww its probably down to what you are using as the from: address in your scripts

As long as you're using a native free-online email address , then it should be ok.

[#5]

 @MisterW

Adding a specific return address on the command line certainly works. Not sure why the change is suddenly necessary?

OK, off now to change my scripts...

Thanks.

[#6]

Not sure why the change is suddenly necessary?

Google have been rolling out Authentication requirements ( SPF and/or DKIM ) for email to gmail accounts over the last few months. Don't think they've defined how the rollout works but certainly if its a gmail address you haven't previously sent to then that seems to get caught. I believe by Feb 24 it will apply to all addresses https://support.google.com/mail/answer/81126#authentication.

Emails sent vai the free-online servers for the free-online.net domain are DKIM signed.