Medical web site - Chapter 24 . Running a Mail Server 619
Chapter 24 . Running a Mail Server 619 Server Configuration Options This section examines two different server configurations. Both configurations provide the same basic features (mail delivery, complete with spam and virus filters) but do so in very different ways. Read the descriptions, decide which configuration is right for you, and then proceed to the Preparing Your System section for information about how your system should be configured before you begin the mail system installation. The features available in these two configurations are a result of how they re being configured and not a result of a lack of features in either sendmail or Postfix. Both programs support nearly the same set of features. The choice of which to configure in what manner was completely arbitrary for the examples in this chapter, and the diversity is intended to help broaden your experience with mail systems. The first configuration demonstrated is based on sendmail, which provides the MTA and MDA functions. Mail retrieval is provided by Qpopper using the POP3 protocol. Direct access to mailboxes is also available using Mutt. All content filtering (spam and virus) takes place before messages are accepted by the server. With the exception of the spam and virus filtering, this is a configuration that you will find on most traditional mail servers. This configuration is suitable for situations in which the following apply: . Users will be downloading messages directly to their systems for viewing. Optionally, Mutt can be installed to allow users to check new messages through SSH (secure shell) connections when they are not at their workstation. . Conditions (business or otherwise) require that the server administrator have the capability to control acceptable message content. The second configuration is based on Postfix, which provides the MTA and remote MDA functions. Local MDA functions, including calls to the content filters and sorting, are provided by maildrop. Mail access is provided through the IMAP facilities in courier-imap. This configuration is suitable for situations in which the following apply: . Messages may be left on the server to allow central backups. . The capability to access all messages remotely is desirable. . Individualized content filter settings are desirable. This second option is great for home systems on broadband connections. As long as your Internet service provider will permit it, you can use your own mail server and get to your mail whether you re at home or away. If you do not have an always-on connection, you can still use this method to run a mail server that is accessible to machines within your own network. Note Note
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