Post is the default program called by send\0(1) to deliver
the message in file to local and remote users. In fact, most of
the features attributed to send in its manual page are performed by
post, with send acting as a relatively simple preprocessor.
Thus, it is post which parses the various header fields, appends
From: and Date: lines, and interacts with the mail transport system.
Post will not normally be called directly by the user.
Post searches the \*(lqTo:\*(rq, \*(lqcc:\*(rq, \*(lqBcc:\*(rq,
\*(lqFcc:\*(rq, and \*(lqResent-xxx:\*(rq header lines of the specified
message for destination addresses, checks these addresses for validity,
and formats them so as to conform to ARPAnet Internet Message Format
protocol, unless the `-noformat' flag is set. This will normally cause
\*(lq@local-site\*(rq to be appended to each local destination
address, as well as any local return addresses. The `-width\ columns'
switch can be used to indicate the preferred length of the header
components that contain addresses.
If a \*(lqBcc:\*(rq field is encountered, its addresses will be used for
delivery, and the \*(lqBcc:\*(rq field will be removed from the message
sent to sighted recipients. The blind recipients will receive an entirely
new message with a minimal set of headers. Included in the body of the
message will be a copy of the message sent to the sighted recipients.
If `-filter\ filterfile' is specified, then this copy is filtered
(re-formatted) by mhl prior to being sent to the blind recipients.
Alternately, if the `-mime' switch is given, then post will use
the MIME rules for encapsulation.
The `-alias\ aliasfile' switch can be used to specify a file that post
should take aliases from. More than one file can be specified, each
being preceded with `-alias'. In any event, the primary alias file is
read first.
The `-msgid' switch indicates that a \*(lqMessage-ID:\*(rq or
\*(lqResent-Message-ID:\*(rq field should be added to the header.
The `-verbose' switch indicates that the user should be informed of
each step of the posting/filing process.
The `-watch' switch indicates that the user would like to watch the
transport system's handling of the message (e.g., local and \*(lqfast\*(rq
delivery).
Under normal circumstances, post constructs the "From:" line of the
message from the user's UNIX username, the full name from the GECOS field of the
passwd file, and the fully-qualified name of the local machine (e.g. `From: "Dan
Harkless" <dan@machine.company.com>'). However, there are three ways to
override these values. Note that they apply equally to "Resent-From:" lines in
messages sent with dist.
The first way is GECOS-based username masquerading. If "mmailid" in the
mts.conf file has been set to non-zero, 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
$SIGNATURE environment variable. This variable overrides the full name
from the GECOS field, even if GECOS-based masquerading is being done.
The third way, which will override either of the previous two, is to specify a
"From:" line manually in the message draft. It will be used as provided (after
alias substitution), but to discourage email forgery, the user's real address
will be used in the SMTP envelope "From:" and in the "Sender:" line. However,
if the system administrator has allowed address masquerading by setting
"mmailid" to non-zero in mts.conf, 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).
^/etc/nmh/mts.conf~^nmh mts configuration file
^/etc/nmh/MailAliases~^global nmh alias file
^/usr/bin/refile~^Program to process Fcc:s
^/usr/lib/nmh/mhl~^Program to process Bcc:s
post does NOT consult the user's .mh\(ruprofile
Standard for the Format of ARPA Internet Text Messages (RFC-822),
mhmail(1), send(1), mh-mail(5), mh-alias(5), mh-tailor(5)
`-alias /etc/nmh/MailAliases'
`-format'
`-nomime'
`-nomsgid'
`-noverbose'
`-nowatch'
`-width\ 72'
`-nofilter'
None
\*(lqReply-To:\*(rq fields are allowed to have groups in them according
to the 822 specification, but post won't let you use them.