SMTPRD

Synopsis

SMTPRD [/?] [/ACCESSLEVEL number] [/BLACKLIST string] [/WHITELIST string] [/ACCEPT string] [/ACCEPTSELFIP[+|-]] [/TEERGRUB[+|-]] [/TRIGGER string] socket

Description

SMTPRD performs an SMTP Relay or a Null SMTP conversation over its input and output. If no socket is specified as an argument, SMTPRD uses its standard input and standard output for input and output. Otherwise, it uses the named socket, which it closes when it has finished with it. The IP address and TCP port number on which SMTP Submission service is thus provided is determined by its parent process, not by SMTPRD itself. Conventionally, the port number is 25 and the IP address is one that is reachable by Internet at large.

SMTPRD is designed to be spawned on demand by TCPSRUN. It can also be spawned by INETD, although the control of client access levels based upon the client's IP address, which TCPSRUN does, will be unavailable as a consequence.

The list of the mailbox domains for which SMTPRD accepts mail, is configured via the /ACCEPT and /ACCEPTSELFIP command-line options. Mail for any other domains will be rejected. So all domains whose mailboxes are stored locally and all domains for which the local mail system knowingly acts as a backup SMTP Relay server should be listed with these options.

Note: The /ACCEPTSELFIP option is a pacification measure, to please people who mis-read RFC 2821 § 4.5.1. It is not, in fact, a requirement that an SMTP Relay server accept mail addressed to postmaster@[a.b.c.d] for the IP addresses a.b.c.d that it listens on. This is, however, what /ACCEPTSELFIP will effect if enabled. It is recommended that one not use this option.

SMTPRD adds received messages to the maildrop directory. The maildrop is taken to be the working directory of the dæmon.

Example RUN file

A "TCPService.RUN" run file, for SMTPRD to be spawned by TCPSRUN, would typically look similar to:

  chdir %MAILQUEUEDIR%
  program %APPS%\JdeBP\IU\Bin\SMTPRD.exe
  argument SMTPRD
  argument %3

TCPSRUN itself would be invoked under RUNSVC, the Service Manager in the OS/2 Command Line Utilities version 2.2, with a run file similar to:

  program %APPS%\JdeBP\IU\bin\TCPSRun.exe
  chdir %_BOOT%:\Config\Services\%1
  argument TCPSRun
  argument 127.0.0.1
  argument smtp
  argument TCPService.RUN

Command-specific options

/ACCEPT: Specify acceptable mailbox domains.
/ACCEPTSELFIP: Specify that the server's own IP address is an acceptable mailbox domain.
/TEERGRUB: Enable teergrubing (tarpitting).
/TRIGGER: Specify the semaphore to signal whenever a message has been submitted.