SMM:08-76
Sendmail Installation and Operation Guide
used); if set but null, the user's TZ variable is used, and if set and non-null the TZ
variable is set to this value.
TrustedUser=user[no short name] The user parameter may be a user name (looked up in
/etc/passwd) or a numeric user id. Trusted user for file ownership and starting the
daemon. If set, generated alias databases and the control socket (if configured)
will automatically be owned by this user.
TryNullMXList [w] If this system is the "best" (that is, lowest preference) MX for a given host, its
configuration rules should normally detect this situation and treat that condition
specially by forwarding the mail to a UUCP feed, treating it as local, or whatever.
However, in some cases (such as Internet firewalls) you may want to try to con-
nect directly to that host as though it had no MX records at all. Setting this option
causes sendmail to try this. The downside is that errors in your configuration are
likely to be diagnosed as "host unknown" or "message timed out" instead of
something more meaningful. This option is disrecommended.
UnixFromLine=fromline
[$l macro] Defines the format used when sendmail must add a UNIX-style From_
line (that is, a line beginning "From<space>user"). Defaults to "From $g $d".
Don't change this unless your system uses a different UNIX mailbox format (very
unlikely).
UnsafeGroupWrites
[no short name] If set (default), :include: and .forward files that are group writable
are considered "unsafe", that is, they cannot reference programs or write directly
to files. World writable :include: and .forward files are always unsafe. Note: use
DontBlameSendmail
instead; this option is deprecated.
UseErrorsTo
[l] If there is an "Errors-To:" header, send error messages to the addresses listed
there. They normally go to the envelope sender. Use of this option causes send-
mail to violate RFC 1123. This option is disrecommended and deprecated.
UserDatabaseSpec=udbspec
[U] The user database specification.
Verbose
[v] Run in verbose mode. If this is set, sendmail adjusts options HoldExpensive
(old c) and DeliveryMode (old d) so that all mail is delivered completely in a sin-
gle job so that you can see the entire delivery process. Option Verbose should
never be set in the configuration file; it is intended for command line use only.
Note that the use of option Verbose can cause authentication information to leak,
if you use a sendmail client to authenticate to a server. If the authentication mech-
anism uses plain text passwords (as with LOGIN or PLAIN), then the password
could be compromised. To avoid this, do not install sendmail set-user-ID root,
and disable the VERB SMTP command with a suitable PrivacyOptions setting.
XscriptFileBufferSize=threshold
[no short name] Set the threshold, in bytes, before a memory-based queue tran-
script file becomes disk-based. The default is 4096 bytes.
All options can be specified on the command line using the -O or -o flag, but most will cause send-
mail to relinquish its set-user-ID permissions. The options that will not cause this are SevenBitIn-
put [7], EightBitMode [8], MinFreeBlocks [b], CheckpointInterval [C], DeliveryMode [d], Error-
Mode [e], IgnoreDots [i], SendMimeErrors [j], LogLevel [L], MeToo [m], OldStyleHeaders [o], Pri-
vacyOptions [p], SuperSafe [s], Verbose [v], QueueSortOrder, MinQueueAge, DefaultCharSet, Dial
Delay, NoRecipientAction, ColonOkInAddr, MaxQueueRunSize, SingleLineFromHeader, and
AllowBogusHELO. Actually, PrivacyOptions [p] given on the command line are added to those
already specified in the sendmail.cf file, i.e., they can't be reset. Also, M (define macro) when
defining the r or s macros is also considered "safe".