MH-MTS(8) [nmh-1.0.4] (MH.6.8) MH-MTS(8)
NAME
mh-mts - the nmh interface to the message transport system
SYNOPSIS
SendMail
Zmailer
MMDF (any release)
stand-alone
DESCRIPTION
THIS IS OUT OF DATE AND NEEDS REWORKING.
nmh can use a wide range of message transport systems to
deliver mail. Although the nmh administrator usually
doesn't get to choose which MTS to use (since it's already
in place), this document briefly describes the interfaces.
When communicating with SendMail, nmh always uses the SMTP
to post mail. Depending on the nmh configuration, SendMail
may be invoked directly (via a fork and an exec), or nmh may
open a TCP/IP connection to the SMTP server on the
localhost.
When communicating with zmailer, the SendMail compatibility
program is required to be installed in /usr/lib. nmh
communicates with zmailer by using the SMTP. It does this
by invoking the /usr/lib/sendmail compatibility program
directly, with the `-bs' option.
When communicating with MMDF, normally nmh uses the mm_
routines to post mail. However, depending on the nmh
configuration, nmh instead may open a TCP/IP connection to
the SMTP server on the localhost.
If you are running a UNIX system with TCP/IP networking,
then it is felt that the best interface is achieved by using
either SendMail or MMDF with the SMTP option. This gives
greater flexibility. To enable this option you append the
/smtp suffix to the mts option in the nmh configuration.
This yields two primary advantages: First, you don't have
to know where submit or SendMail live. This means that nmh
binaries (e.g., post ) don't have to have this information
hard-coded, or can run different programs altogether; and,
second, you can post mail with the server on different
systems, so you don't need either MMDF or SendMail on your
local host. Big win in conserving cycles and disk space.
Since nmh supports the notion of a server search-list in
this respect, this approach can be tolerant of faults. Be
sure to set servers: as described in mh-tailor(8) if you use
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MH-MTS(8) [nmh-1.0.4] (MH.6.8) MH-MTS(8)
this option.
There are four disadvantages to using the SMTP option:
First, only UNIX systems with TCP/IP are supported. Second,
you need to have an SMTP server running somewhere on any
network your local host can reach. Third, this bypasses any
authentication mechanisms in MMDF or SendMail. Fourth, the
file /etc/hosts is used for hostname lookups (although there
is an exception file). In response to these disadvantages
though: First, there's got to be an SMTP server somewhere
around if you're in the Internet or have a local network.
Since the server search-list is very general, a wide-range
of options are possible. Second, SMTP should be fixed to
have authentication mechanisms in it, like POP. Third, nmh
won't choke on mail to hosts whose official names it can't
verify, it'll just plug along (and besides if you enable the
DUMB configuration options, nmh ignores the hosts file
altogether).
FILES
/usr/freeware/lib/nmh/etc/mts.conf nmh mts configuration file
PROFILE COMPONENTS
None
SEE ALSO
MMDF-II: A Technical Review, Proceedings, Usenix Summer '84
Conference
SENDMAIL -- An Internetwork Mail Router
mh-tailor(8), post(8)
DEFAULTS
None
CONTEXT
None
BUGS
The /usr/freeware/lib/nmh/etc/mts.conf file ignores the
information in the MMDF-II tailoring file.
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