cyrus+sendmail+lmtpunix connection refused by localhost

[Chris Harms]

Hello,

We have recently started to experience an inconsistent problem after 
restarting cyrus and sendmail after a nightly backup script runs.  All 
services seem to start properly, but mail delivery is deferred with 
sendmail logging

dsn=4.4.1, stat=Deferred: Connection refused by localhost

It appears to be something in lmtp, but we aren't sure what exactly.  We 
are using the socket for lmtpunix delivery.  The magic bullet seemed to 
be stopping all services and removing /var/run/cyrus-master.pid and some 
old lmtp lock files, but then this may have been coincidental.  I found 
a few similar reports on Google, but no definite answers to this problem.

Any insight as to why this would just start happening out of the blue 
would be most appreciated.

Thank you,
Chris Harms

# additional info

# Software versions
cyrus 2.2.12
sendmail 8.13.6

# /var/imap/socket
srwxrwxrwx 1 root  root  0 May 16 22:36 lmtp

# cyrus.conf
  lmtp          cmd="lmtpd" listen="lmtp" prefork=0
  lmtpunix      cmd="lmtpd" listen="/var/imap/socket/lmtp" prefork=1