Issue Emails not sending, deferred - connection timed out/network is unreachable - Plesk Obsidian 18.0.39 / Ubuntu 20.04.3

[Mahann]

Hi,

I set up my first Plesk server, and am having trouble with Postfix.

All outgoing emails are getting deferred, and not sent.

This is the mail log:

2021-10-22 08:09:56    postfix/smtp[167172]    BC094BD279: to=<***@***>, relay=none, delay=67223, delays=67132/0.01/91/0, dsn=4.4.1, status=deferred (connect to alt1.aspmx.l.google.com[2607:f8b0:400e:c00::1b]:25: Network is unreachable)
2021-10-22 08:09:56    postfix/smtp[167172]    connect to alt1.aspmx.l.google.com[2607:f8b0:400e:c00::1b]:25: Network is unreachable
2021-10-22 08:09:56    postfix/smtp[167172]    connect to alt1.aspmx.l.google.com[173.194.202.27]:25: Connection timed out
2021-10-22 08:09:56    postfix/smtp[167173]    9509EBD9AD: to=<***@gmail.com>, relay=none, delay=61481, delays=61390/0.02/91/0, dsn=4.4.1, status=deferred (connect to alt2.gmail-smtp-in.l.google.com[142.250.115.27]:25: Connection timed out)
2021-10-22 08:09:56    postfix/smtp[167175]    EDB5ABD29D: to=<***@gmail.com>, relay=none, delay=64761, delays=64670/0.02/91/0, dsn=4.4.1, status=deferred (connect to alt2.gmail-smtp-in.l.google.com[142.250.115.27]:25: Connection timed out)
2021-10-22 08:09:56    postfix/smtp[167173]    connect to alt2.gmail-smtp-in.l.google.com[142.250.115.27]:25: Connection timed out
2021-10-22 08:09:56    postfix/smtp[167175]    connect to alt2.gmail-smtp-in.l.google.com[142.250.115.27]:25: Connection timed out
2021-10-22 08:09:56    postfix/smtp[167171]    C9800BD056: to=<***@***>, relay=none, delay=65179, delays=65088/0.01/91/0, dsn=4.4.1, status=deferred (connect to alt2.aspmx.l.google.com[2607:f8b0:4023:1004::1b]:25: Network is unreachable)
2021-10-22 08:09:56    postfix/smtp[167174]    E896DBD0B3: to=<***@***>, relay=none, delay=64923, delays=64831/0.02/91/0, dsn=4.4.1, status=deferred (connect to alt2.aspmx.l.google.com[2607:f8b0:4023:1004::1a]:25: Network is unreachable)
2021-10-22 08:09:56    postfix/smtp[167170]    CC78FBD2A0: to=<***@gmail.com>, relay=none, delay=62708, delays=62617/0.01/91/0, dsn=4.4.1, status=deferred (connect to alt2.gmail-smtp-in.l.google.com[142.250.115.27]:25: Connection timed out)
2021-10-22 08:09:56    postfix/smtp[167171]    connect to alt2.aspmx.l.google.com[2607:f8b0:4023:1004::1b]:25: Network is unreachable
2021-10-22 08:09:56    postfix/smtp[167171]    connect to alt1.aspmx.l.google.com[173.194.202.27]:25: Connection timed out
2021-10-22 08:09:56    postfix/smtp[167174]    connect to alt2.aspmx.l.google.com[2607:f8b0:4023:1004::1a]:25: Network is unreachable
2021-10-22 08:09:56    postfix/smtp[167174]    connect to alt1.aspmx.l.google.com[173.194.202.27]:25: Connection timed out
2021-10-22 08:09:56    postfix/smtp[167170]    connect to alt2.gmail-smtp-in.l.google.com[142.250.115.27]:25: Connection timed out
2021-10-22 08:09:26    postfix/smtp[167172]    connect to alt2.aspmx.l.google.com[142.250.115.27]:25: Connection timed out
2021-10-22 08:09:26    postfix/smtp[167175]    connect to alt1.gmail-smtp-in.l.google.com[2607:f8b0:400e:c00::1b]:25: Network is unreachable
2021-10-22 08:09:26    postfix/smtp[167175]    connect to alt1.gmail-smtp-in.l.google.com[173.194.202.27]:25: Connection timed out
2021-10-22 08:09:26    postfix/smtp[167173]    connect to alt1.gmail-smtp-in.l.google.com[2607:f8b0:400e:c00::1b]:25: Network is unreachable
2021-10-22 08:09:26    postfix/smtp[167173]    connect to alt1.gmail-smtp-in.l.google.com[173.194.202.27]:25: Connection timed out
2021-10-22 08:09:26    postfix/smtp[167171]    connect to alt2.aspmx.l.google.com[142.250.115.27]:25: Connection timed out
2021-10-22 08:09:25    postfix/smtp[167170]    connect to alt1.gmail-smtp-in.l.google.com[2607:f8b0:400e:c00::1a]:25: Network is unreachable
2021-10-22 08:09:25    postfix/smtp[167170]    connect to alt1.gmail-smtp-in.l.google.com[173.194.202.27]:25: Connection timed out
2021-10-22 08:09:25    postfix/smtp[167174]    connect to alt2.aspmx.l.google.com[142.250.115.27]:25: Connection timed out
2021-10-22 08:08:56    postfix/smtp[167172]    connect to aspmx.l.google.com[2404:6800:4003:c02::1a]:25: Network is unreachable
2021-10-22 08:08:56    postfix/smtp[167172]    connect to aspmx.l.google.com[142.251.12.27]:25: Connection timed out
2021-10-22 08:08:56    postfix/smtp[167173]    connect to gmail-smtp-in.l.google.com[2404:6800:4003:c04::1b]:25: Network is unreachable
2021-10-22 08:08:56    postfix/smtp[167173]    connect to gmail-smtp-in.l.google.com[172.217.194.27]:25: Connection timed out
2021-10-22 08:08:56    postfix/smtp[167175]    connect to gmail-smtp-in.l.google.com[2404:6800:4003:c04::1b]:25: Network is unreachable
2021-10-22 08:08:56    postfix/smtp[167175]    connect to gmail-smtp-in.l.google.com[172.217.194.27]:25: Connection timed out
2021-10-22 08:08:55    postfix/smtp[167174]    connect to aspmx.l.google.com[2404:6800:4003:c04::1a]:25: Network is unreachable
2021-10-22 08:08:55    postfix/smtp[167174]    connect to aspmx.l.google.com[142.251.12.27]:25: Connection timed out
2021-10-22 08:08:55    postfix/smtp[167170]    connect to gmail-smtp-in.l.google.com[2404:6800:4003:c04::1a]:25: Network is unreachable
2021-10-22 08:08:55    postfix/smtp[167171]    connect to aspmx.l.google.com[2404:6800:4003:c0f::1a]:25: Network is unreachable
2021-10-22 08:08:55    postfix/smtp[167171]    connect to aspmx.l.google.com[74.125.24.27]:25: Connection timed out
2021-10-22 08:08:55    postfix/smtp[167170]    connect to gmail-smtp-in.l.google.com[172.217.194.26]:25: Connection timed out
2021-10-22 08:08:24    postfix/qmgr[51914]    EDB5ABD29D: from=<test@***>, size=1162, nrcpt=1 (queue active)
2021-10-22 08:08:24    postfix/qmgr[51914]    E896DBD0B3: from=<test@***>, size=1145, nrcpt=1 (queue active)
2021-10-22 08:08:24    postfix/qmgr[51914]    9509EBD9AD: from=<test@***>, size=598, nrcpt=1 (queue active)
2021-10-22 08:08:24    postfix/qmgr[51914]    BC094BD279: from=<wordpress@***>, size=1220, nrcpt=1 (queue active)
2021-10-22 08:08:24    postfix/qmgr[51914]    C9800BD056: from=<wordpress@***>, size=1332, nrcpt=1 (queue active)
2021-10-22 08:08:24    postfix/qmgr[51914]    CC78FBD2A0: from=<test@***>, size=1174, nrcpt=1 (queue active)

Just tried sending to an address other than Google, same issue:

2021-10-22 09:06:14    postfix/smtp[188601]    6E92BBD9F9: to=<***@***>, relay=none, delay=61, delays=0.17/0.01/60/0, dsn=4.4.1, status=deferred (connect to ***.mail.protection.outlook.com[104.47.71.138]:25: Connection timed out)
2021-10-22 09:06:14    postfix/smtp[188601]    connect to ***.protection.outlook.com[104.47.71.138]:25: Connection timed out
2021-10-22 09:05:44    postfix/smtp[188601]    connect to ***.protection.outlook.com[104.47.71.202]:25: Connection timed out

• I can ping the destination SMTP server IPs fine from shell.
• I couldn't telnet to Google's servers on any port (25, 465, 587)
• I can telnet to Outlook Online's servers on port 587

Any ideas why this is happening and how to fix?


Thanks in advance!


PS: Hosting on Azure, and the Azure NSG is not blocking port 25.

 

[Nik G]

hello @Mahann ,

unfortunately there are no miracles.

• I couldn't telnet to Google's servers on any port (25, 465, 587)

it looks like this is network misconfiguration.

you can check with 'iptables -L -n' is it your firewall or not.
in case there is no local firewall rules - this is azure config.

 

[Mahann]

Nothing in firewall rules.

Did some more research and found that Azure may block port 25.

Submitted a support request to Microsoft, will see how that goes.