On Wed, Aug 4, 2010 at 10:39, Dominik Storck <domi...@storck.net> wrote: > > This has been working perfectly for years. Now the number of recipients > for some of > these lists have increased to more than 200. > > When a mail is sent to these recipients mail delivery starts as expected > but stops > short before end of list. The exact count changes, probably due to different > state of of concurrent mail queue entries. > > The error message is an "unknown mail transport error", the mail stays > in the queue and > delivery starts over again from the beginnig until I remove the mail > from the queue. > > I believe there is some limit to 200 recipients, queue entries or whatever.
I'd speculate it's low open file limit in operating system. I had this once when my 'everyone' alias exceeded several hundred users. See ulimit -n Increase it in your postfix startup script to, say, 100000, and observe the difference. Regards, Andrzej
