Path: utzoo!attcan!uunet!husc6!think!ames!amdahl!tron
From: tron@amdahl.uts.amdahl.com (Ronald S. Karr)
Newsgroups: comp.mail.uucp
Subject: Re: BSMTP - Its time has come
Message-ID: <8cxtXf2ifC1010ZZURE@amdahl.uts.amdahl.com>
Date: 18 Jun 88 09:30:28 GMT
References: <14605@uunet.UU.NET> <10127@mcdchg.UUCP> <10266@ncc.Nexus.CA> <1787@van-bc.UUCP> <10267@ncc.Nexus.CA> <9593@g.ms.uky.edu>
Reply-To: tron@amdahl.uts.amdahl.com (Ronald S. Karr)
Organization: Amdahl Coup, UTS Products Hen house
Lines: 147

In article <1787@van-bc.UUCP> sl@wimsey.bc.ca (10 Stuart Lynne) writes:
>Something else which could (should) be done is to get BSMTP implemented at
>UUNET. 

The Smail3.1 mailer, currently in Alpha test, handles a batched form of
SMTP.  It allows a site to a create a transport that sends a message
formatted as:

	HELO site.domain
	MAIL FROM:<sender>
	RCPT TO:<recipient>
	...
	DATA
	From: user (name)
	Subject: ...
	To: whomever

	body...
	.
	QUIT

Smail3.1 can then send this over UUCP using a command such as:

	uux - host!rsmtp

or:
	uux - host!rmail -bS

Error recover on the recipient side is handled by returning mail
to the sender identified in the "RCPT TO:" command.

Paritially formed transactions (without the HELO and QUIT) can also be
accumlated in a file or directory and periodically delivered in one
one large batch of SMTP commands with one UUCP transaction.

This method of delivery, or any number of other methods, can be
selected on a per-host basis.

Other features in Smail3.1 are:

*  Multiple alias files (using YP, DBM, sorted or unsorted ASCII files).

*  Multiple path files.

*  Networking with SMTP over TCP/IP, wherever the socket calls exist.

*  Mailing list directories (create a mailing list merely by creating
   a file in these directories--great with sticky directories).

*  The ability to call arbitrary programs to calculate paths.

*  Fairly simple site configuration to add new forms for
   aliasing/forwarding, host routing and delivery.

*  Standard hooks for adding new C routines to perform aliasing,
   host routing, delivery, or database lookup.

*  Adequate security to allow users to specify shell commands and
   mailbox files in alias and .forward files.

*  Command line compatibility with sendmail, allowing sendmail to
   be entirely replaced simply by copying smail3.1 to /usr/lib/sendmail.

The following is an example of how one would batch together messages
to be sent using batched SMTP in one UUCP transaction:

First of all, create an entry in a routing configuration file to
define a paths file:

	# define a paths file created by the pathalias program
	paths:	driver=pathalias,
		# this file maps hosts to transports:
		method=/usr/lib/smail/methods/uucp-transports;

		# the paths file is stored as a DBM database:
		file=/usr/lib/smail/paths, proto=dbm

Then, create the file /usr/lib/smail/methods/uucp-transports to
state which hosts should receive mail over batched SMTP:

	# map hosts to transports
	uunet	batched_smtp
	cbosgd	batched_smtp
	*	uux	# all other hosts are delivered to remote rmail

Then, entries are added to a transport description file:

	# deliver using uux-->rmail
	uux:	driver=pipe,	# deliver by calling a program
		max_chars=200,	# at most 200 chars in command line
		max_addrs=5,	# up to 5 addresses per call
		uucp,		# limit envelope addresses to UUCP forms
		from;		# expects a From_ line

		# deliver using the following command:
		cmd="/usr/bin/uux - -r -g$grade $host!rmail $(($user)$)"

	# accumulate batched SMTP commands in a file based on host:
	batched_smtp:
		driver=appendfile, # deliver by appending to a file
		-max_chars,	# no limit on chars of address per invocation
		-max_addrs,	# no limit on addresses per invocation
		-hbsmtp;	# use batched SMTP without HELO and QUIT

		# deliver to a file based on the name of the host:
		file=/usr/spool/smail/smtp_outq/$host

Then, to send these files periodically to remote hosts, use a script
such as the following (executed from cron):

	#!/bin/sh

	cd /usr/spool/smail/smtp_outq
	for host in *; do
		# move to prevent inconsistent copy of file
		mv $host .$host
		# if one more transaction being added, allow to complete
		sleep 10
		# send to remote host:
		uux - -r $host!rsmtp < .$host
		rm -f .$host
	done

	exit 0

Anybody interested in more information on smail (such as the current
set of man pages) can send mail to:

	info-smail-request@uts.amdahl.com
	{decwrl,sun,uunet}!amdahl!info-smail-request

to get on the smail3.1 information mailing list.

The Smail3.1 mailer is related to the Smail2.5 mailer both by name and
through discussions with Larry Auton and Mark Horton at the last summer
USENIX (1987).  It is only slightly related by code.  The hope is that
this will replace the previous version of smail at some time in the
future.  Hopefully, if Larry and Mark haven't become too bored waiting
for significant progress this will still occur.

The authors of Smail3.1 are Ronald S. Karr (myself) and Landon Curt Noll.
Both of us are employees at Amdahl Corp. of Sunnyvale CA.
-- 
	tron	|-<=>-|		ARPAnet:  amdahl!tron@Sun.COM
      tron@uts.amdahl.com	UUCPnet:  {decwrl,sun,uunet}!amdahl!tron
[views above shouldn't be viewed as Amdahl views, or as views from Amdahl, or
 as Amdahl views views, or as views by Mr. Amdahl, or as views from his house]