Postfix Mail Being Refused

Ziycon

** Couldn't find anywhere else relevant, please move if a better forum exists.

I have setup a new mail server (CentOS 7 & Postfix) to solely handle all out going mail from load balanced web nodes, I also have hosted mail (MX record) with a hosting provider that handles all incoming mail and the mailboxes etc.

My issue is, the new mail server I setup is as you can guess very new and when I try to send a mail on the submission of a contact form on the website the below is shown in the server mail log.

Jun 2 21:46:11 localhost postfix/smtp[29911]: CF16760B: host gmail-smtp-in.l.google.com[66.102.1.27] said: 421-4.7.0 [212.71.249.130 15] Our system has detected that this message is 421-4.7.0 suspicious due to the very low reputation of the sending IP address. 421-4.7.0 To protect our users from spam, mail sent from your IP address has 421-4.7.0 been temporarily rate limited. Please visit 421 4.7.0 https://support.google.com/mail/answer/188131 for more information. y186si3852692wmy.130 - gsmtp (in reply to end of DATA command)
Jun 2 21:46:11 localhost postfix/smtp[29911]: CF16760B: to=<test@gmail.com>, relay=alt1.gmail-smtp-in.l.google.com[64.233.165.26]:25, delay=0.93, delays=0.17/0.01/0.37/0.38, dsn=4.7.0, status=deferred (host alt1.gmail-smtp-in.l.google.com[64.233.165.26] said: 421-4.7.0 [212.71.249.130 15] Our system has detected that this message is 421-4.7.0 suspicious due to the very low reputation of the sending IP address. 421-4.7.0 To protect our users from spam, mail sent from your IP address has 421-4.7.0 been temporarily rate limited. Please visit 421 4.7.0 https://support.google.com/mail/answer/188131 for more information. q20si13791240lff.23 - gsmtp (in reply to end of DATA command))

I've added the server and verified it with Google Postmaster, I know this might help with gmail but how can I build the reputation of the server if mail is already being blocked due to a low reputation of the mail servers IP?

Any help greatly appreciated.

jmcc

Linode IP range. No reverse DNS on the IP?

Regards...jmcc

Graham

Ziycon wrote: »

I've added the server and verified it with Google Postmaster, I know this might help with gmail but how can I build the reputation of the server if mail is already being blocked due to a low reputation of the mail servers IP?

Any help greatly appreciated.

I wouldn't even try to build up the reputation.

Can you use one of the transactional email providers like sendgrid, we went from 100% in the spam folder to 0% instantly.

They offer a free trial which converts to a free 100 emails a day plan after 30 days.

gearoid!

I looks you setup a mail relay, and you should have setup your SPF and DKIM records to mitigate those type of issues especially when using mail relay services.  Try to lookup SPF and DKIM records and try to set them up.

Also, try mailgun as a relay, and test your server with it.