Need Help - Postfix Maybe...

[Melbosa]

Hi,

I need a solution quickly to solve this problem scenario:

I have a client with multiple email local servers.

I need to setup a gateway for SMTP that decides where to route email locally based on email address.  I believe this can be achieved through a postfix transport map install, but I haven't been able to get it to work at all.

So what I want to do is:

* Setup an SMTP Gateway to accept email from world
* Decide based on email address which email server to relay the mail too
* Kicker is the email addresses could be same domain different email server (so joe@company.com goes to server A and susan@company.com goes to server B)

Anyone any good with postfix?

[Melbosa]

Doh minutes after posting I fixed my issue... crazy!

[Lazybones]

Maybe you should post a sanitized config so the rest of us can use your solution in the future.

[Melbosa]

So to set this up with Postfix:
* Install Linux Distro of Choice
*Setup Postfix (do your proper changes to the postfix main config) and disable Sendmail
* Test Postfix can receive email
* Setup relay domains you want:

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postconf -e 'relay_domains = yourdomain.ca, yourotherdomain.ca
* Enable Transport Maps and setup your transport file (usually /etc/postfix/transport) to point at your smtp servers (at the end of the file):

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yourdomain.ca          smtp:[192.168.1.5]
yourotherdomain.ca     smtp:[192.168.1.10]
* OPTIONAL: If you want to relay based on email address, add it before the above lines in the transport file:

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user@yourdomain.ca          smtp:[192.168.1.5]
user@yourotherdomain.ca     smtp:[192.168.1.10]
* Most of the time you need to create a postmap after editing your Transport File:

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postmap hash:/etc/postfix/transport
* For every edit, you must reload your postfix:

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postfix reload

Point your inbound SMTP at this new install and your golden!

[Melbosa]

As you can see with the above, if you have users split between servers but same domain (or migrating to new email system like I was doing), you can easily accomplish this by:

* put your users in your transport file, but point them at the new server as you move them (if say doing a migration):

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user1@yourdomain.ca      smtp:[192.168.1.5]
user2@yourdomain.ca      smtp:[192.168.1.5]

* but have a catch-all for any not listed pointing at your old server or any not handled:

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yourdomain.ca      smtp:[192.168.1.10]

It is a top-down search so make sure your catch-all is at the end.  In this example, email to user1 and user2 go to server 192.168.1.5 and email to everyone else goes to server 192.168.1.10 for the domain yourdomain.ca

[Lazybones]

nice!