Martin Allan Jensen put forth on 9/19/2009 8:06 AM: > Hi all, > > The company I work for have approximately nine mail servers, including > Postfix, qmail, sendmail and exim. > They would like to make ONE SMTP relay host server so that all their > customers can use their SMTP server to send mail through. > The customers already get their incoming mail through their mail servers. > > I fail to see a way to make this possible without creating an entirely > open relay, or creating a database with usernames and passwords and use > SASL.
I fail to understand why this is considered anything remotely beyond simple to moderate difficulty. If I understand you correctly (maybe I don't) all the communication you're referring to is server to server (MTA<->MTA). There will be no desktop PCs (MUAs) directly submitting mail to your new "master relay server", correct? If this is the case, setting up a http://www.postfix.org/STANDARD_CONFIGURATION_README.html#firewall should do the trick with little fuss. The only "difficult" part is that you would have setup a local SASL username and password for each remote MTA that will connect to relay mail. Even if the remote MTA count ("your customers") is 250, this is still utterly simple to accomplish, _assuming_ that the other MTA admins aren't brain dead individuals. Have each remote MTA connect with the proper SASL username and password in order to relay mail. Like I say, if there are no desktop PCs in the mix, this is absolutely simple to accomplish, and without going through a multitude of databases to pull out usernames and passwords for thousands of users. But, like I said, maybe I'm not fully comprehending your post. It was pretty sparse on detail and clarity, regarding the actual _structure_ (think network diagram) of what you're trying to do. -- Stan
