Why the outbound email delivery is failing with Connection timed out errors?

[ghevge]

Why the outbound email delivery is failing with Connection timed out errors?

I just set up mail stelwart mail server, I am able to receive emails but the outbound emails are not being delivered. In the mail-server logs I see Connection timed out:

2024-07-17T13:16:16.550055Z  INFO delivery{id=186524424766795779 return_path="[email protected]" nrcpt=1 size=1177}:attempt{domain="gmail.com" attempt_number=0}: smtp::outbound::delivery: context="connect" event="failed" mx="alt2.gmail-smtp-in.l.google.com" reason=I/O error: Connection timed out (os error 110)
2024-07-17T13:16:16.550180Z  INFO delivery{id=186524424766795779 return_path="[email protected]" nrcpt=1 size=1177}:attempt{domain="gmail.com" attempt_number=0}: smtp::outbound::delivery: context="connect" event="failed" mx="alt2.gmail-smtp-in.l.google.com" reason=I/O error: Network is unreachable (os error 101)
2024-07-17T13:17:28.230038Z  INFO delivery{id=186524017325813762 return_path="[email protected]" nrcpt=1 size=2433}:attempt{domain="yahoo.com" attempt_number=0}: smtp::outbound::delivery: context="connect" event="failed" mx="mta5.am0.yahoodns.net" reason=I/O error: Connection timed out (os error 110)

DNS entries are defined, so is the rDNS entry

What am I missing ?

Thanks

[yannikbloscheck]

Could it maybe be that your hosting provider blocks outgoing connections on the port 25 by default?

[ghevge]

@yannikbloscheck yeah, the cloud provider was indeed blocking port 25. I've ended up switching to another provide which allows this.