Allow authenticated relay for Postfix
Posted on 2011-03-12
Hello all, I have a development machine that gets moved around a lot on different ISPs (Comcast/ATT/etc), all of which have issues with sending mail. Though they often offer a relay option, ATT (the current provider) is more of an issue due to the From email addresses having to be verified. I would like to stop dealing with all of this and use a mail server that is stationed at one location.
This server is in a collocation facility and currently just processes mail like any other mail server would for certain organizations. I would like to use this mail server in place of the ISP relay options mentioned above, but obviously this type of relay is turned off in Postfix as it only sends on behalf of known entities. I don't want to mess with the way the Postfix is currently running, that is fine, but I would like to add the functionality that, for authenticated users, the mail server will act as a relay server in the same way Comcast/ATT would act above. I know how to setup my development server to use a relay, but I am not clear on how to setup the colo mail server to act as a relay option for the development server.
So I am looking for guidance on how to do this. All of the stuff I'm finding online is about setting up Postfix to work with an outbound relay server already available, not setting up a Postfix server to act as a relay. The colo mail server currently authenticates users that send/receive mail through PAM. I believe TLS & SASL are options to use, I have used SASL in the past for Comcast.
Are there any resources/tutorials that do what I want, or maybe some quick suggested configuration changes that would help me get this up and running quickly? I am not a Postfix expert by any means, so any help you can offer will be greatly appreciated.
My ideal setup would be able to set the relayhost in my development machine to be mail.server.com:587 (or some port, 25 is not an option), and then use SASL to define a username/password already in place on the mail.server.com through basic PAM authentication. I then need the mail.server.com to listen and act as a relay on 587 (it currently does not, only port 25) and relay any email that is authenticated. I know this probably very simple, Postfix is very flexible, but again, it's just not my area of expertise. Thanks again, everyone.