--- name: "post" section: "8mh" platform: "linux" package: "nmh" version: "1.8-3" release: "Debian 13 (Trixie)" platforms: ["linux"] url: "https://new.carta.tech/post/8mh" --- # post(8mh) deliver an nmh message ## NAME post - deliver an nmh message ## SYNOPSIS **/usr/lib/mh/post** \[**-help**\] \[**-version**\] \[**-alias** *aliasfile*\] \[**-filter** *filterfile*\] \[**-nofilter**\] \[**-format** \| **-noformat**\] \[**-mime** \| **-nomime**\] \[**-msgid** \| **-nomsgid**\] \[**-messageid** *localname* \| *random*\] \[**-verbose** \| **-noverbose**\] \[**-watch** \| **-nowatch**\] \[**-width** *columns*\] \[**-mts** *smtp* \| *sendmail/smtp* \| *sendmail/pipe*\] \[**-sendmail** *program*\] \[**-server** *servername*\] \[**-port** *portname/number*\] \[**-sasl**\] \[**-nosasl**\] \[**-saslmech** *mechanism*\] \[**-user** *username*\] \[**-tls**\] \[**-initialtls**\] \[**-notls**\] \[**-snoop**\] *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)](/mh-profile/5.md) 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 any message that contains 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** or **sendmail/smtp** 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)](/mh-profile/5.md). 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)](/mh-profile/5.md) 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* ## SEE ALSO [*mhmail*(1)](/mhmail/1.md), [*send*(1)](/send/1.md), [*mh-mail*(5)](/mh-mail/5.md), [*mh-alias*(5)](/mh-alias/5.md), [*mh-profile*(5)](/mh-profile/5.md), [*mh-tailor*(5)](/mh-tailor/5.md) *Standard for the Format of ARPA Internet Text Messages* (RFC 822) ## 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.