Lightweight LMTP daemon to avoid overkill MTA

[Marc Roos]

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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