[Pkg-exim4-users] Delivery batching by LMTP

[Roger Lynn]

Hi,

I'm running an up to date Debian Wheezy with the Debian packages of
exim4-daemon-heavy and dovecot-imapd.

Local deliveries are by Dovecot's LMTP server, which is working fine, except
that they're not batching - each recipient is delivered individually.

My exim transport configuration is:

lmtp:
  driver = lmtp
  socket = /var/run/dovecot/lmtp
  batch_max = 20
#  delivery_date_add
#  envelope_to_add

When delivering the same message to two local users, exim logs this (I've
changed the domain name):

2012-10-16 12:02:10 1TO4uO-0002n5-6W <= root at example.co.uk U=root P=local S=315
2012-10-16 12:02:10 1TO4uO-0002n5-6W => roger <RLynn at example.co.uk>
R=local_user T=lmtp S=326
2012-10-16 12:02:10 1TO4uO-0002n5-6W => test <test at example.co.uk>
R=local_user T=lmtp S=326

And Dovecot LMTP logs this:

Oct 16 12:02:10 alphonse dovecot: lmtp(10737): Connect from local
Oct 16 12:02:10 alphonse dovecot: lmtp(10737, roger):
iXrCFrI+fVDxKQAAAFrtIw: sieve: msgid=<E1TO4uO-0002n5-6W at mail.example.co.uk>:
stored mail into mailbox 'Server'
Oct 16 12:02:10 alphonse dovecot: lmtp(10737): Disconnect from local: Client
quit (in reset)
Oct 16 12:02:10 alphonse dovecot: lmtp(10737): Connect from local
Oct 16 12:02:10 alphonse dovecot: lmtp(10737, test): jXrCFrI+fVDxKQAAAFrtIw:
sieve: msgid=<E1TO4uO-0002n5-6W at mail.example.co.uk>: stored mail into
mailbox 'INBOX'
Oct 16 12:02:10 alphonse dovecot: lmtp(10737): Disconnect from local: Client
quit (in reset)

Why is exim delivering individually, instead of batching? If I telnet to
LMTP and deliver by hand, LMTP handles multiple addresses fine.

"# exim -d-all+transport roger test" reports:

>>>>>>>>>>>>>>>> Local deliveries >>>>>>>>>>>>>>>>
--------> roger at example.co.uk <--------
driver lmtp does not depend on domain
driver lmtp does not depend on local_part
lmtp transport entered
using socket /var/run/dovecot/lmtp
  LMTP<< 220 alphonse.example.co.uk Dovecot ready.
  LMTP>> LHLO mail.example.co.uk
  LMTP<< 250-alphonse.example.co.uk
  LMTP<< 250-8BITMIME
  LMTP<< 250-ENHANCEDSTATUSCODES
  LMTP<< 250 PIPELINING
  LMTP>> MAIL FROM:<root at example.co.uk>
  LMTP<< 250 2.1.0 OK
  LMTP>> RCPT TO:<roger at example.co.uk>
  LMTP<< 250 2.1.5 OK
  LMTP>> DATA
  LMTP<< 354 OK
  LMTP>> writing message and terminating "."
writing data block fd=6 size=326 timeout=300
  LMTP<< 250 2.0.0 <roger at example.co.uk> iXrCFrI+fVDxKQAAAFrtIw Saved
  LMTP>> QUIT
  LMTP<< 221 2.0.0 Client quit
lmtp transport yields 1
lmtp transport returned OK for roger at example.co.uk
LOG: MAIN
  => roger <RLynn at example.co.uk> R=local_user T=lmtp S=326
--------> test at example.co.uk <--------
lmtp transport entered
using socket /var/run/dovecot/lmtp
  LMTP<< 220 alphonse.example.co.uk Dovecot ready.
  LMTP>> LHLO mail.example.co.uk
  LMTP<< 250-alphonse.example.co.uk
  LMTP<< 250-8BITMIME
  LMTP<< 250-ENHANCEDSTATUSCODES
  LMTP<< 250 PIPELINING
  LMTP>> MAIL FROM:<root at example.co.uk>
  LMTP<< 250 2.1.0 OK
  LMTP>> RCPT TO:<test at example.co.uk>
  LMTP<< 250 2.1.5 OK
  LMTP>> DATA
  LMTP<< 354 OK
  LMTP>> writing message and terminating "."
writing data block fd=7 size=326 timeout=300
  LMTP<< 250 2.0.0 <test at example.co.uk> jXrCFrI+fVDxKQAAAFrtIw Saved
  LMTP>> QUIT
  LMTP<< 221 2.0.0 Client quit
lmtp transport yields 1
lmtp transport returned OK for test at example.co.uk
LOG: MAIN
  => test <test at example.co.uk> R=local_user T=lmtp S=326
LOG: MAIN
  Completed QT=10s

Thank you for any assistance,

Roger