How to get all your mail going out of one IP address with POSTFIX

If you have multiple IPs (ETH0,ETH0:0, etc) running on a server with Postfix, chances are you are going to run into the problem of Postfix not using the mail IP that has the matching MX record to send mail.

When this happens most of the mail servers will label your mail as SPAM and/or reject it.

You can force Postfix to use the main servers IP address by adding the following lines to your /etc/postfix/main.cf:
smtp_bind_address = 1.1.1.1

*You would replace 1.1.1.1 with the main IP of your own server.
Restart Postfix with /etc/init.d/postfix restart

This might cause your mail to backup on the server if your have other services  that might need a configuration tweak to continue working correctly, check your mail queue with this:
postqueue -p

If you see mail backing up in that queue for failed connections to 127.0.0.1, then you might have to start making some tweaks. If not, then you should be OK.


If you have AMAVIS running on the server then you might need to make this tweak for AMAVIS to properly work. Create the file /etc/amavis/conf.d/60-custom. Add the following line:
@inet_acl = qw( 127.0.0.1 [::1] 1.1.1.1 );

Restart AMAVIS with /etc/init.d/amavis restart

Now check the Postfix queue with postqueue -p again. If there is any mail still there try flushing it out with postqueue -f. The recheck it after a couple of seconds with postqueue -p again. It should be all gone now.

Upgraded most of my boxes to Debian 7 Wheezy and ISPCONFIG

For the most part I'm happy to be on Debian 7 with ISPCONFIG, as DTC was taking forever to update their code to make it Debian 7 compatible; and my clients were installing software requiring the latest PHP and MYSQL. So I really didn't have much of a choice in the matter.

I like and dis-like a few things about ISPCONFIG.

LIKES:

• Offers and Handles multiservers very well.
• easy to install guides
• well documented
• many howto guides for just about every option
• cheap billing module

DISLIKES:

• creating a website or sub-domains does not automatically create a DNS entries/mail domains/etc, you have to expect your customers to know what they are doing. It's not as user-friendly in that aspect. It would be nice if it offered a dummy mode or wizards for users. In this aspect DTC was nice to do everything for you when you added a domain. Then you just had to do any customizations required, but the basics where created for you.