Chapter 5. Securing Your Installation

Of all the things that can happen to your SMTP server, probably the worst is having it abused as an open relay—a server that relays mail to third parties without your permission. This will consume a lot of bandwidth (which can be costly), eat up server resources (possibly slowing down or stopping other services), and can be expensive in both time and money. A more serious consequence is that your e-mail server will probably end up on one or more blacklists, and any e-mail server that refers to those lists will refuse to accept any mail from your server until you have proven it to be relay safe. If you need to use e-mail in order to carry out business, you will have a big problem.

This chapter will explain how ...

Get Linux E-mail now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.