post (8) - Linux Manuals

post: deliver a message


post - deliver a message


/usr/libexec/nmh/post [-alias aliasfile] [-filter filterfile] [-nofilter] [-format | -noformat] [-mime | -nomime] [-msgid | -nomsgid] [-messageid localname | random] [-verbose | -noverbose] [-watch | -nowatch] [-width columns] [-mts smtp | sendmail/smtp | sendmail/pipe] [-server servername] [-port portname/number] [-sasl] [-nosasl] [-saslmaxssf ssf] [-saslmech mechanism] [-user username] [-tls] [-initialtls] [-notls] file [-version] [-help]


is the default program called by send 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 a ``Date:'' line, and interacts with the mail transport system. Post will not normally be called directly by the user.

Post searches the ``To:'', ``cc:'', ``Bcc:'', ``Fcc:'', and ``Resent-xxx:'' 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 ``@local-site'' 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 ``Bcc:'' field is encountered, its addresses will be used for delivery, and the ``Bcc:'' 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 ``Message-ID:'' or ``Resent-Message-ID:'' field should be added to the header.

The -messageid switch selects the style used for the part appearing after the @ in ``Message-ID:'', ``Resent-Message-ID:'', and ``Content-ID:'' header fields. The two acceptable options are localname (which is the default), and random. With localname, the local hostname is used. With random, a random sequence of characters is used instead. Note that the -msgid switch must be enabled for this switch to have any effect.

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 ``fast'' delivery).

Under normal circumstances, post uses the ``From:'' line in the message draft as the identity of the originating mailbox. A ``From:'' line is required in all message draft. By default the message composition utilities such as comp, repl and mhmail will automatically place a ``From:'' line in the message draft. There are two ways to override this behavior, however. Note that they apply equally to ``Resent-From:'' lines in messages sent with dist.

The first way is to supply a ``Sender:'' 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 ``From:'' line, a ``Sender:'' line is required. If an ``Envelope-From:'' line is supplied when multiple addresses are given in the ``From:'' line, a ``Sender:'' header will be generated using the value of the ``Envelope-From:'' line, if the ``Envelope-From:'' line is not blank.

The second way is to supply a ``Envelope-From:'' 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 ``From:'' line and a ``Sender:'' line (if one is supplied). The ``Envelope-From:'' 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.

The mail transport system default is provided in /etc/nmh/mts.conf but can be overriiden here with the -mts switch.

If nmh is using the SMTP MTA, the -server and the -port switches can be used to override the default mail server (defined by the servers entry in /etc/nmh/mts.conf ).

If nmh has been compiled with SASL support, the -sasl and -nosasl switches will enable and disable the use of SASL authentication with the SMTP MTA. Depending on the SASL mechanism used, this may require an additional password prompt from the user (but the netrc file can be used to store this password, as described in the mh-profile(5) man page). The -saslmech switch can be used to select a particular SASL mechanism, and the -user switch can be used to select a authorization userid to provide to SASL other than the default. The credentials profile entry in the mh-profile(5) man page describes the ways to supply a username and password.

If SASL authentication is successful, nmh will attempt to negotiate a security layer for session encryption. Encrypted data is labelled with `(sasl-encrypted)' and `(sasl-decrypted)' when viewing the SMTP transaction with the -snoop switch. The -saslmaxssf switch can be used to select the maximum value of the Security Strength Factor. This is an integer value and the exact meaning of this value depends on the underlying SASL mechanism. A value of 0 disables encryption.

If nmh has been compiled with TLS support, the -tls and -initialtls switches will require the negotiation of TLS when connecting to the SMTP MTA. The -tls switch will negotiate TLS as part of the normal SMTP protocol using the STARTTLS command. The -initialtls will negotiate TLS immediately after the connection has taken place, before any SMTP commands are sent or received. Encrypted data is labelled with `(tls-encrypted)' and `(tls-decrypted)' when viewing the SMTP transction with the -snoop switch. The -notls switch will disable all attempts to negotiate TLS.


^/etc/nmh/mts.conf~^nmh mts configuration file
^/etc/nmh/MailAliases~^global nmh alias file
^/usr/bin/refile~^Program to process Fcc:s
^/usr/libexec/nmh/mhl~^Program to process Bcc:s


post does NOT consult the user's .mh_profile


`-alias' defaults to /etc/nmh/MailAliases
`-messageid localname'
`-width 72'




``Reply-To:'' fields are allowed to have groups in them according to the RFC 822 specification, but post won't let you use them.


mhmail(1), send(1), mh-mail(5), mh-alias(5), mh-profile(5), mh-tailor(5)

Standard for the Format of ARPA Internet Text Messages (RFC 822)