34.1.1 Pre-V8.7 Command-Line Option Declarations

Prior to version 8.7, option names that are declared on the command line could be only a single character long:

-oXargument     prior to V8.7

The -o switch (lowercase o) is immediately followed (with no intervening space) by the one-letter name of the option (here, X). Depending on the option selected, an argument may be required. If that argument is present, it must immediately follow the option name with no intervening space. Only one option may be specified for each -o switch.

Under V8 sendmail a space may appear between the -o and the X, but no space may exist between the X and its argument. This is because V8 sendmail uses getopt(3) to parse its command line.

34.1.2 V8.7 Multicharacter Options in the Command Line

Beginning with version 8.7, option names may be single-character or multicharacter. Single-character options are declared with the -o (lower case) switch as described above. Multicharacter options are declared with a -O (uppercase) switch:

-OLongName=argument        beginning with V8.7
 
 uppercase

Space may optionally exist between the -O and the LongName. Space may not exist between the LongName, the =, and the argument unless they are quoted:

-O "LongName = argument"

Only one option may be specified for each -O switch.

The sendmail program ignores case when it considers multicharacter names. Therefore the following three command lines have the same effect, and none produces an error:

-OQueueDirectory=/var/tmp
-Oqueuedirectory=/var/tmp
-OQuEuEdIrEcToRy=/var/tmp

34.1.3 Appropriateness of Options

Some options are intended for use only on the command line and make little or no sense when used in the configuration file. Options that are inappropriate in the configuration file are shown in Table 34.1.

34.1.4 Options that Are Safe

It is common practice to install sendmail so that it runs with root privilege. Security considerations normally require that sendmail give up that privilege for most command-line options specified by the ordinary user. But the ordinary user can specify a few options that allow sendmail to keep its root privilege. Those options are called "safe" and are shown in Table 34.2.

V8.7.3 was accidentally released with the LogLevel (L) option marked as not safe. For example, the AliasFile (A) option (location of the aliases file) is unsafe (and is not in Table 34.2). If you were to send mail by specifying a new location with the AliasFile option, sendmail would change its identity from root to an ordinary user (you), thus preventing sendmail from being able to queue its mail:

/var/spool/mqueue: Permission denied

Note that prior to V8.8.4, the DontInitGroups and TryNullMXList options were wrongly set to safe. This is yet another reason to always upgrade to the latest version of sendmail.