-
-Under normal circumstances, \fIpost\fR constructs the "From:" line of the
-message from the user's login name, the full name from the GECOS field of the
-passwd file, and the fully\-qualified name of the local machine (or the value of
-"localname" in mts.conf, if set). An example is "From: Dan Harkless
-<dan@machine.company.com>". There are four ways to override these values,
-however. Note that they apply equally to "Resent\-From:" lines in messages sent
-with \fIdist\fR.
-
-The first way is GECOS\-based username masquerading. If the "masquerade:" line
-in mts.conf contains "mmailid", this processing is activated. If a user's GECOS
-field in the passwd file is of the form "Full Name <fakename>" then "fakename"
-will be used in place of the real username. For instance, a GECOS field of "Dan
-Harkless <Dan.Harkless>" would result in "From: Dan Harkless
-<Dan.Harkless@machine.company.com>". Naturally if you were doing something like
-this you'd want to set up an MTA alias (e.g. in /etc/aliases) from, for
-instance, "Dan.Harkless" to "dan".
-
-The second way to override default construction of "From:" is to set the
-\fB$SIGNATURE\fR environment variable. This variable overrides the full name
-from the GECOS field, even if GECOS\-based masquerading is being done. This
-processing is always active, and does not need to be enabled from mts.conf.
-
-The third way is controlled by the "user_extension" value of "masquerade:" line
-of mts.conf. When that's turned on, setting the \fB$USERNAME_EXTENSION\fR
-environment variable will result in its value being appended the user's login
-name. For instance, if I set \fB$USERNAME_EXTENSION\fR to "+www", my "From:"
-line will contain "Dan Harkless <dan+www@machine.company.com>" (or
-"Dan.Harkless+www" if I'm using mmailid masquerading as well). Recent versions
-of sendmail automatically deliver all mail sent to \fIuser\fR+\fIstring\fR to
-\fIuser\fR. qmail has a similar feature which uses '\-' as the delimiter by
-default, but can use other characters as well.
-
-The fourth method of address masquerading is to specify a "From:" line manually
-in the message draft. It will be used as provided (after alias substitution),
-but normally, to discourage email forgery, the user's \fIreal\fR address will be
-used in the SMTP envelope "From:" and in a "Sender:" header. However, if the
-"masquerade:" line of mts.conf contains "draft_from", the SMTP envelope "From:"
-will use the address given in the draft "From:", and there will be no "Sender:"
-header. This is useful in pretending to send mail "directly" from a remote POP3
-account, or when remote email robots give improper precedence to the envelope
-"From:". Note that your MTA may still reveal your real identity (e.g.
-sendmail's "X\-Authentication\-Warning:" header).
-
-If nmh has been compiled with SASL support, the `\-sasl' switch will enable
+.PP
+Under normal circumstances,
+.B post
+uses the \*(lqFrom:\*(rq line in the message draft as the identity of
+the the originating mailbox. A \*(lqFrom:\*(rq line is required in
+all message draft. By default the message composition utilities such
+as
+.BR comp ,
+.B repl
+and
+.B mhmail
+will automatically place a \*(lqFrom:\*(rq line in the message draft.
+There are two ways to override this behavior, however.
+Note that they apply equally to \*(lqResent\-From:\*(rq lines in messages sent
+with
+.BR dist .
+.PP
+The first way is to supply a \*(lqSender:\*(rq line. The value of this
+field will be used as the originating mailbox identity when submitting the
+message to the mail transport system. If multiple addresses are
+given in the \*(lqFrom:\*(rq line, a \*(lqSender:\*(rq line is
+.BR required .
+If an \*(lqEnvelope-From:\*(rq line is supplied when multiple addresses
+are given in the \*(lqFrom:\*(rq line, a \*(lqSender:\*(rq header will
+be generated using the value of the \*(lqEnvelope-From:\*(rq line,
+.B if
+the \*(lqEnvelope-From:\*(rq line is not blank.
+.PP
+The second way is to supply a \*(lqEnvelope-From:\*(rq line. The value
+of this field will be used as the originating mailbox identity when
+submitting the message to the mail transport system. This will override
+both the value of the \*(lqFrom:\*(rq line and a \*(lqSender:\*(rq line
+(if one is supplied). The \*(lqEnvelope-From:\*(rq line is allowed to
+have a blank value; if the value is blank, then the mail transport system
+will be instructed to not send any bounces in response to the message.
+Not all mail transport systems support this feature.
+.PP
+The mail transport system default is provided in
+.I %etcdir%/mts.conf
+but can be overriiden here with the
+.B \-mts
+switch.
+.PP
+If nmh is using the SMTP MTA, the
+.B \-server
+and the
+.B \-port
+switches can be used to override the default mail server (defined by the
+.RI servers
+entry in
+.I %etcdir%/mts.conf
+).
+.PP
+If
+.B nmh
+has been compiled with SASL support, the
+.B \-sasl
+and
+.B \-nosasl
+switches will enable and disable
projects / mmh / blobdiff