Lightweight LMTP daemon to avoid overkill MTA

[William Edwards]

I ended up 'hacking' LMTP support into the external spam filter. Someone else already contributed 'real' patches to implement LMTP support, so once I go live with this mail platform it should be stable.


Met vriendelijke groeten,

William Edwards
T. 040 - 711 44 96
E. wedwards at cyberfusion.nl




 
----- Original Message -----
From: Marc Roos (M.Roos at f1-outsourcing.eu)
Date: 12/11/19 19:14
To: dovecot (dovecot at dovecot.org), wedwards (wedwards at cyberfusion.nl)
Subject: RE: Re[2]: Lightweight LMTP daemon to avoid overkill MTA

Yes I am running sendmail next to dovecot on backend servers. That works
ok. I have some problems with re-routing mail in a proxy setup.



-----Original Message-----
To: Marc Roos; dovecot
Subject: Re[2]: Lightweight LMTP daemon to avoid overkill MTA


Hi,

I was unclear in my question. The spam filter is only able to deliver
mail over SMTP, not over LMTP.. So I would still need some kind of
daemon that listens for SMTP and then offers incoming email to Dovecot's
LMTP socket.


Met vriendelijke groeten,

William Edwards
T. 040 - 711 44 96
E. wedwards at cyberfusion.nl





----- Original Message -----
From: Marc Roos (M.Roos at f1-outsourcing.eu)
Date: 12/11/19 18:59
To: dovecot (dovecot at dovecot.org), wedwards (wedwards at cyberfusion.nl)
Subject: RE: Lightweight LMTP daemon to avoid overkill MTA

Yes dovecot, /etc/dovecot/conf.d/20-lmtp.conf ;)

service lmtp {
chroot =
client_limit = 1
drop_priv_before_exec = no
executable = lmtp
extra_groups = $default_internal_group
group =
idle_kill = 0
inet_listener lmtp {
  address =
  haproxy = no
  port = 24
  reuse_port = no
  ssl = no
}
privileged_group =
process_limit = 0
process_min_avail = 0
protocol = lmtp
service_count = 0
type =
unix_listener lmtp {
  group =
  mode = 0666
  user =
}
user =
vsz_limit = 18446744073709551615 B
}


-----Original Message-----
To: dovecot at dovecot.org
Subject: Lightweight LMTP daemon to avoid overkill MTA

Hi,

My situation is as follows.

-An internet-facing spam filter relays email to destination mail server
(Dovecot) with SMTP.
- Dovecot should take email and deliver it to user's mailboxes. I guess
I'd need LMTP for this.
- An external SMTP relay is already in place. I am thinking of using
Dovecot submission to relay to the external relaying cluster.

So, both relaying and routing are done externally - the Dovecot machine
should only store mail. Of course, there should also be a mechanism that
takes care of local delivery to Dovecot, like LMTP. Usually, I would use
an MTA like Exim to take care of local delivery. I feel like a
fully-featured MTA is overkill, though, as all other roles such an MTA
would fulfill - relaying and spam filtering - are fulfilled on external
servers.

Q: Does anyone know of a lightweight LMTP daemon that can take care of
local delivery to Dovecot without the need for a full MTA?

With kind regards,

William Edwards
T. 040 - 711 44 96
E. wedwards at cyberfusion.nl



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