IN THIS CHAPTER
Understanding mail server security issues
Securely authenticating email users
Encrypting email transfer between server and clients with SSL
Preventing your server from being used to relay spam
Protecting your users from junk mail and malware
Mac OS X Server can provide a full range of email services for your organization: handling all incoming and outgoing mail (even from multiple domains), offering users the option to check their mail from a web browser, running mailing lists, filtering messages for viruses and spam, and even (starting with Snow Leopard) delivering push email and letting users filter mail on the server before it reaches their inboxes. And all these features can be configured using the easy-to-understand administrative tools included with Mac OS X Server.
However, before you begin using the mail server, you should be aware of certain security risks and the steps you can take to minimize them. With an optimal configuration, you can be confident that your users' passwords and messages won't be intercepted in transit, that spammers won't be able to use your server to send out junk mail, and that the majority of junk mail sent to your users from the outside is caught before it gets to them.