Change outgoing postfix IP address


First of all sorry for my english.

I have a server with centos 6.5, virtualmin and postfix 2.6.6. My problem is that gmail is marking emails sent from my server as spam. I have correct SPF and DKIM, so I assume the problem is the IP (allthought I checked the ip in a blacklist checker and not appears as Spam in any list).

I want to change the outgoing IP address from default IP to other IP I have already installed in the server. is it possible? I try to add the next line in /etc/ but doesn’t work (obviously changing IP ADDRESS for the real IP I desire):

smtp_bind_address = IP ADDRESS

I don’t need different outgoing IP addresses per domain, but I need change the postfix outgoing IP address for all domains in server.

Thank you very much in advance.


How many IP’s you have on that server? I’m asking because it could be that Gmail/Google blocked entire block and if this is the case nothing can help you aside of changing the host or go for external email service like GoogleApps.

The bad part is you cant check Gmail blacklist because is not public. On top of that Google will remove IP from the blacklist using their algorithms to check if IP (or entire IP block) is safe what can take at least from 1-3 months up to a year and any abuse regardless how small or big will reset this timer.

My advice:

  1. Check if you have properly set SPF, DKIM and rDNS. You must have all 3 if you want Gmail to accept your emails and not mark them as spam. Missing just one is like missing all 3 from Google point of view.

  2. Send one email to your Gmail account and check mailllog and see if you get return code for that email what could give you the clue what is wrong.

  3. In case everything is in order and you dont see anything wrong in your maillog that means Google have your IP or entire IP block on blacklist. Talk with your host and see if other clients have same problem as you and if they have that means entire IP block is blacklisted. Your host then probably dont have proper setup to prevent this to happen or just dont care and my advice is to change the host.

Hi Diabolico,

Thank you very much for your answer. Now gmail mark the mails from my server as valid.

The problem was the rDNS.

Thank you again.


The problem was the rDNS.
Good news and no problem, i’m glad i could help.

Sorry to bring old tread but I couldn’t find the original question.

How to config postfix to use different than the main interface for outgoing email?