sendmail, 4th Edition

V8.7 Configuration File Declarations

Beginning with V8.7, option names can be single-character or multicharacter. A space is used to differentiate between single-character and multicharacter (long) names:

O LongName=argument       ←  beginning with V8.7
 ↑
 a space (not a tab)

Whenever the O configuration command is followed by a space (not a tab), everything following that space is taken as the declaration of a multicharacter option. Unlike single-letter option names, multicharacter names are interpreted by sendmail without regard to case. Therefore, the following three examples all produce the same effect:

O QueueDirectory=/var/spool/mqueue
O queuedirectory=/var/spool/mqueue
O QuEuEdIrEcToRy=/var/spool/mqueue

Optional space (not tab) characters can surround the = character:

O QueueDirectory = /var/spool/mqueue
                ↑ ↑
               spaces, not tabs

Multicharacter names in the configuration file ought not be abbreviated or expressed in shorthand:

O QueueDirectory=/var/spool/mqueue     ← good
O QueueDir=/var/spool/mqueue          ← bad, but allowed

Failure to use the full multicharacter name will cause sendmail to print spurious warnings every time it is run. The possible warnings are listed in Multicharacter name shorthand on page 950.