[OmniOS-discuss] OmniOS sendmail suitable for Internet mail hub?

[Bob Friesenhahn]

On Sun, 7 Feb 2016, Dale Ghent wrote:

> Future plans and thoughts on MTAs in OmniOS specifically:
>
> You mentioned my mail, maybe you saw the one last night where I 
> proposed cutting sendmail out of illumos-gate entirely (in due 
> time). Right now my plans are to cease the inclusion and use of 
> illumos-gate's sendmail in OmniOS, and replace it with a small, 
> lightweight MTA called DMA (Dragonfly Mail Agent.) The only thing 
> this will do is send mails to either the local user's spool in 
> /var/mail, or to a remote host via MX record lookup or defined 
> smarthost with TLS/SMTP-AUTH as an option. It also does basic 
> /etc/mail/aliases lookups and a outgoing queuing ability. That's it, 
> and a solution that I believe is suitable for /most/ OmniOS 
> use-cases (ie; 1 of many servers in a datacenter which never accept 
> incoming mail, but may send a lot to somewhere remotely.)

The above sounds reasonable.  The sendmail rules below are what I am 
using (for many years) to create a simple forwarding mailer on all but 
a true 'mailhost':

   divert(0)dnl
   VERSIONID(`@(#)simplesystems-subordinate.mc February 1, 2014')
   OSTYPE(`solaris8')dnl
   DOMAIN(`solaris-generic')dnl
   FEATURE(`nullclient', `mailhost$?m.$m$.')dnl

   LOCAL_NET_CONFIG
   R$* < @ $* .$m. > $*    $#esmtp $@ $2.$m $: $1 < @ $2.$m. > $3

Your approach avoids the nasty mess of sendmail related files (and 
dependencies), which pollute zones and systems intended only to 
provide storage access.

> This DMA package will be mediated under IPS, and provide the usual 
> /usr/lib/sendmail, /usr/sbin/sendmail, /usr/bin/mailq symlinks to 
> itself. The reason why these links will be mediated is because my 
> plan is to provide a better sendmail, also IPS-mediatetd, than is 
> what on current offer from illumos-gate. This sendmail will continue 
> to have all the SUN_* options enabled in the code, but it being 
> freed from illumos-gate means we can flush out additional features 
> in it and track newer versions faster. Because of the MTA mediation 
> in IPS, one can even implement other MTAs, such as postfix or 
> opensmtpd or ... whatever your heart wants.
>
> Sound reasonable?

Your approach sounds reasonable as long as the larger improved 
sendmail is available (as an OmniOS package) to optionally install in 
place of the tiny MTA.  The tiny MTA should be the default.

Many of us have working sendmail setups and want to avoid the time and 
risk of needing to compile a sendmail package for ourselves or switch 
to a different mail system, even if the different mail system does not 
require 1200 pages to describe it.

Bob
-- 
Bob Friesenhahn
bfriesen at simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/