How to setup mail relay in linux using postfix

[Raja_b02]

Hi All,

Can someone guide me to setup mail relay using postfix in RedHat Linux 6.4.

Regards,
Raja

[Matti_Kurkela]

Some more information is needed.

Do you want to:

A) make your RHEL 6.4 system relay mail to some other central mail server? (e.g. your company's main mail server, or your ISP's mail server)

or

B) make your RHEL 6.4 system to be a central mail server that accepts relayed mail from other hosts?

A) is fairly easy, but you'll need some more details:

• Does the central mail server require the use of SSL/TLS and/or authentication?
• Should you use the traditional SMTP port (25) or the newer mail submission port (587)?
• If authentication is required, are you required to use a particular authentication type? (i.e. is plaintext authentication required/acceptable/forbidden?) Do you have the necessary username/password for the central mail server?

B) is more complex, since you'll want to make sure only legitimate users can use your mail server to send outgoing mail, or else your system *will* sooner or later be abused to send lots and lots of junk mail to random email addresses all over the world. That would get your mail server blacklisted, which is not a good thing.