Hello everybody

This is my first post here.
I use Zimbra for almost 1 year now and it has been a very good experience.
I managed to setup a zimbra server following the excellent guides you guys provide.

2 days ago and I started getting this error in all external connected imap accounts and I simply cannot receive any more mails.
I am able to receive mails in zimbra own accounts but not in imap accounts on external servers.

This is the error I get:
A network service error has occurred.
method: ImportDataRequest
msg: system failure: Unable to connect to mail store: DataSource: { id=38e796ce-6f53-4837-a6d0-69e87896dbd7, type=imap, isEnabled=true, name=Helder Alves, host=imap.graficapacense.pt, port=993, connectionType=ssl, username=ha0893@graficapacense.pt, folderId=262 }
code: service.FAILURE
detail: soap:Receiver
trace: btpool0-38:1264674549919:1c495c3a8fe13d2a

helder.alves@intranet.graficapacense.pt0_28ce1a6eb64c85e3a08c26d5c2630eeb131029e6_69643d3 3363a37336264373965612d653735632d346161642d3837303 02d6564633539626661656537613b6578703d31333a3132363 43735393133383132353b747970653d363a7a696d6272613b
This is Zimbra version:
Client Version: 5.0.14_GA_2850.UBUNTU8
Client Release: 20090303190551
Build Date: 20090303-1918

Thanks in advance for your help.
Helder Alves