This is an error which may be logged in the Windows event log

It is event 4547 from the source 'VPOP3'

If the event message DLL is not correctly installed it may display as:

The description for Event ID ( 4547 ) in Source ( VPOP3 ) cannot be found. The local computer
may not have the necessary registry information or message DLL files to display messages 
from a remote computer. You may be able to use the /AUXSOURCE= flag to retrieve this 
description; see Help and Support for details. 
The following information is part of the event: timeout expired

This happens if PostgreSQL is not responding to the connection request from VPOP3.

One cause we have found is if the pg_attribute table in the database is too large. A known problem with the version of PostgreSQL shipped with VPOP3 (9.1.1) is that if this table is very large, it may take an exceptionally long time for PostgreSQL to start.

You can check if this is the problem. Wait until PostgreSQL has started, then from a command prompt in the VPOP3\pgsql\bin directory run

psql -U postgres -p 5433 -c "select reltuples from pg_class where relname='pg_attribute'" vpop3

(the password is 'pgsqlpass')

If the displayed value is over about 100,000, then this may be the problem. Contact support@pscs.co.uk for assistance. Note that this command may take a long time to run if it is this problem.

Also check the disk fragmentation, and defrag the disk if necessary.