[Dovecot] Errors

[vmstech]

Hi All

I intermittently get these kind of errors when connecting to my beta2
imap dovecot:

reported error 0x8004df0b:'Outlook is unable to download folder (null)
from the imap email server for account mymailhost.com'. Error the server
is unavailable.

Receiveing Reported error (0x800CC0F):'The connection to the server was
interrupted'

While these are from outlook - I often get one simiar to the first one
in my evolution clients.  Are these things that can be best managed with
some sort of configuration change? What might be other possible causes
of these (apart from a power cut to the server?

thx

Glenn