Ubuntu Manpage: post - deliver an nmh message

NAME

       post - deliver an nmh message

SYNOPSIS


       /usr/lib/mh/post [-help] [-version] [-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]
            [-sendmail program] [-server servername] [-port portname/number] [-sasl] [-nosasl] [-saslmech
            mechanism] [-user username] [-tls] [-initialtls] [-notls] file

DESCRIPTION

post 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, but can be replaced by the user with a postproc profile component that will have file as its
final argument. See mh-profile(5) for more information on postproc.

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. The body of this new message will contain a copy of the message
sent to the sighted recipients, either marked up with the indicator text "Blind-Carbon-Copy" or
encapsulated as a MIME digest.

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.

If a “Dcc:” field is encountered and the sendmail/pipe mail transport method is not in use, its addresses
will be used for delivery, and the “Dcc:” field will be removed from the message. The blind recipients
will receive exactly the same message as the sighted recipients. *WARNING* Recipients listed in the
“Dcc:” field receive no explicit indication that they have received a “blind copy”. This can cause blind
recipients to inadvertently reply to all of the sighted recipients of the original message, revealing
that they received a blind copy. On the other hand, since a normal reply to a message sent via a “Bcc:”
field will generate a reply only to the sender of the original message, it takes extra effort in most
mailers to reply to the included message, and so would usually only be done deliberately, rather than by
accident.

post rejects all messages that contain a “Dcc:” field if the sendmail/pipe mail transport method is used.

The -alias aliasfile switch can be used to specify a file that post should read aliases from. More than
one file can be specified, with each being preceded by -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 drafts. 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 defined in /etc/nmh/mts.conf but can be overridden here with the
-mts switch.

If nmh is using sendmail/pipe, as its mail transport system, the -sendmail switch can be used to override
the default sendmail program.

If nmh is using the SMTP MTA, the -server and -port switches can be used to override the default mail
server and port. The default server is set with servers in /etc/nmh/mts.conf, and the default port is
submission, 587.

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 mh-profile(5). The -saslmech switch can be used to select a particular SASL mechanism, and
the -user switch can be used to select an authorization userid to provide to SASL, other than the
default. The credentials profile entry in mh-profile(5) 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. Base64-encoded data is wrapped with `b64<>'. (Beware that the
SMTP transaction may contain authentication information either in plaintext or easily decoded base64.)

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 transaction with the -snoop switch.
Base64-encoded data is wrapped with `b64<>'. (Beware that the SMTP transaction may contain
authentication information either in plaintext or easily decoded base64.) The -notls switch will disable
all attempts to negotiate TLS.

If port 465 is specified and none of the TLS switches were enabled, -initialtls will be implied if TLS
support was compiled in. Though port 465 for SMTPS (SMTP over SSL) was deregistered by IANA in 1998, it
is still used for that service.

post filters out header lines with names beginning with “Nmh-” (case insensitive) from the message draft.
Those lines are reserved for internal nmh use.

FILES

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

PROFILE COMPONENTS

       post does not consult the user's .mh_profile

DEFAULTS

       `-alias' defaults to /etc/nmh/MailAliases
       `-format'
       `-nomime'
       `-nomsgid'
       `-messageid localname'
       `-noverbose'
       `-nowatch'
       `-width 72'
       `-nofilter'

CONTEXT

       None

BUGS

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

nmh-1.7.1                                          2016-10-17                                          POST(8mh)