Dear Sir,
We're using Postfix on a Linux server to send emails via SMTP. Emails are relayed from our server.
Most emails reach their destination fine, however certain addresses never receive our emails. When I check the mailq I see the following:
Apr 6 04:25:30 srv postfix/smtp[16320]: connect tocluster1.us.messagelabs.com[216.82.249.179]:25: Connection timed out
Apr 6 04:25:30 srv postfix/smtp[16320]: 8271142813674: to=<abc@domain.com>, relay=none, delay=21560, delays=21410/0.02/150/0, dsn=4.4.1, status=deferred (connect to cluster1.us.messagelabs.com[216.82.249.179]:25: Connection timed out)
Apr 6 04:33:30 srv postfix/smtp[16856]: connect tocluster14.us.messagelabs.com[216.82.241.197]:25: Connection timed out
Apr 6 04:33:30 srv postfix/smtp[16857]: connect tocluster14.us.messagelabs.com[216.82.241.197]:25: Connection timed out
Apr 6 04:34:00 srv postfix/smtp[16856]: connect tocluster14.us.messagelabs.com[216.82.248.67]:25: Connection timed out
Apr 6 04:34:00 srv postfix/smtp[16857]: connect tocluster14.us.messagelabs.com[216.82.248.67]:25: Connection timed out
Apr 6 04:34:30 srv postfix/smtp[16856]: connect tocluster14.us.messagelabs.com[216.82.248.67]:25: Connection timed out
Apr 6 04:34:30 srv postfix/smtp[16857]: connect tocluster14.us.messagelabs.com[216.82.241.197]:25: Connection timed out
Apr 6 04:35:00 srv postfix/smtp[16856]: connect tocluster14.us.messagelabs.com[216.82.241.197]:25: Connection timed out
Apr 6 04:35:00 srv postfix/smtp[16857]: connect tocluster14.us.messagelabs.com[216.82.248.67]:25: Connection timed out
Apr 6 04:35:31 srv postfix/smtp[16856]: connect tocluster14.us.messagelabs.com[216.82.248.67]:25: Connection timed out
I have checked the blacklists on mxlookup.com and our domain has all green ticks (nobody is blacklisting us).
Also I have checked our IP address here: http://ipremoval.sms.symantec.com/lookup/ and it says The IP address you submitted, xxx.xxx.xxx.xxx, does not have a negative reputation and therefore cannot be submitted for investigation.
I can give you our IP or hostname in a private message if you need it.
Kindly helps us to resolve this issue.
Regards
Mahadev