Cyrus Postfix LMTP tuning

John Madden jmadden at
Thu Oct 13 15:10:06 EDT 2011

> Our Postfix relays (there are 3) seem to make one lmtp connection per
> message, rather than sending multiple messages down a single connection.
> Do any Cyrus+Postfix users out there have tuning recommendations?  I see a
> lot of postfix lmtp_* config options, but I know little about Postfix.

I make no guarantees about these, but try this out:

lmtp_destination_concurrency_limit = 50
lmtp_destination_recipient_limit = 5000
lmtp_connection_cache_on_demand = no
lmtp_data_done_timeout = 3600s

It's been a couple years, but I definitely had oddball issues with LMTP 
under load and somewhere along the line these options fixed them.  YMMV. 
  The usual RTFineM about these applies too:


John Madden / Sr UNIX Systems Engineer
Office of Technology / Ivy Tech Community College of Indiana

     Free Software is a matter of liberty, not price. To understand
     the concept, you should think of Free as in 'free speech,' not
     as in 'free beer.' -- Richard Stallman

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