[Dovecot] Errors

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