[Dovecot] OpenBSD and too many open files

[Bryan Vyhmeister]

I posted some questions a few months back and received lots of great  
help in getting my dovecot/postfix/LDAP setup working. Initially, I  
ran into the pipe failed too many open files error. I am running this  
setup on OpenBSD/sparc64 4.1-stable and so I put dovecot in its own  
class and upped the maxfiles setting for that class. This was back  
with dovecot 1.0 and everything worked fine. I just recently upgraded  
to dovecot 1.0.2 from ports and now I am having the same problems  
again. I moved kern.maxfiles for that class from 2048 up to 3404 and  
yet I still run into the error. When I do, I have to restart dovecot  
to get things running again.

Output of: su -c dovecot root -c 'ulimit -a'
time(cpu-seconds)    unlimited
file(blocks)         unlimited
coredump(blocks)     unlimited
data(kbytes)         1048576
stack(kbytes)        8192
lockedmem(kbytes)    634482
memory(kbytes)       1898080
nofiles(descriptors) 3404
processes            1044

sysctl kern.maxfiles gives:
kern.maxfiles=3404

My main IMAP accounts reside on this server and I have somewhere in  
the 25000 range of stored messages. Could this be causing the issue?  
I only have maybe a dozen other users using this server right now but  
I am planning on putting 500 users on it soon. I added another heavy  
IMAP user shortly before these problems started but I don't know if  
that has anything to do with it or not. Likewise, I am not sure if  
the dovecot 1.0.2 upgrade had any effect either although it did  
coincide. Any ideas? Thank you.

Bryan