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24.7 Interrelating OptionsAt the end of this chapter we describe all the options in detail, with those descriptions in alphabetical order for easy lookup. Here, we present them grouped by application with only a brief description. 24.7.1 File Locationssendmail knows the location of only its configuration file.[6] Options in the configuration file tell sendmail where all other files and directories are located. The options that specify file locations are summarized in Table 24-6. All file location options are of type string.
File and directory locations should be expressed as full pathnames. Use of relative names will cause the location to become relative to the queue directory or, for some options, cause the name to be interpreted as something other than a file or directory. 24.7.2 The QueueSeveral options combine to determine your site's policy for managing the sendmail queue (see Chapter 11). Among them is one that specifies the location of the queue directory and another that sets the permissions given to files in that directory. The list of many options that affect the queue is shown in Table 24-7.
24.7.3 Managing AliasesIn addition to knowing the location of the aliases file, some options determine how that file and its associated database files will be used. For example, there is an option that tells sendmail to check the right side of the aliases for validity. The various aliases-related options are shown in Table 24-8.
24.7.4 Controlling Machine LoadSeveral options control the sendmail program's behavior under high-machine-load conditions. They are intended to reduce the impact of sendmail on machines that provide other services and to help protect sendmail from overburdening a machine. The list of options that determine and help to prevent high-load conditions is shown in Table 24-9.
24.7.5 Connection CachingConnection caching improves the performance of SMTP-transported mail. In processing the queue or delivering to a long list of recipients, keeping a few SMTP connections open (just in case another message is for one of those same sites) will improve the speed of transfers. Caching is of greatest benefit on busy mail hub machines but can benefit any machine that sends a great deal of network mail. Table 24-10 lists the options that determine how connections will be cached.
24.7.6 Problem SolvingThe sendmail program offers a few options that will help in locating and solving some mail delivery problems. Table 24-11 lists the available options.
Other means to solve problems are described in Chapter 16, which discusses the -d debugging command-line switch, and in Chapter 14 (specifically Section 14.2), which covers the -X traffic-logging command-line switch. 24.7.7 Other OptionsThe sendmail program supports a vast array of options, each of which is described at the end of this chapter. For now, study each one well enough to get a basic feeling for what it does. Then, as you gain experience with sendmail, you'll know where to look for the particular option that will meet your needs. ![]() |
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