Recently much attention has been paid to e-mail viruses transmitted by flaws in certain client software. Up the line from most of those clients, however, is a larger-scale server that transmits mail across the Internet. Some might say that security starts at the server. Some of these servers process millions of messages during a week’s time how do you know if the server is secure?

There are generally two types of Internet mail servers. Mail transfer agents (MTAs) take care of routing your message to the right place on the Internet and notifying you if the transfer can’t be accomplished. Mail user agents (MUAs) bring mail directly to your mail client.

This article examines one MTA and its equivalents and one of the primary protocols MUAs use for mail services. Sendmail has been an integral part of the Internet for almost as long as there has been an Internet. Internet Message Access Protocol (IMAP) is becoming one of the more important and useful protocols used by MUAs. A number of measures can be taken to run both services in a secure and reliable manner; this article examines the related issues involved in establishing and maintaining server security.

By Informer at Linux Exposed.

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