[imp] Horde, IMP and eXtremail

[Robert Walter]

Hi,
 
I'm using Horde with IMP 3.2 RC2 (with other versions, i got the same
problem) and eXtremail 1.5.7 as Mail-Server.
When I try to open a e-mail with IMAP, IMP don't show me the Mail-Body. 
When I try to connect over POP3, he shows me that the password or 
username is incorrect. If I try to connect to another Mail-Server (not 
mine) he works greate.
Other IMAP and POP3 Clients (like Outlook, Mozilla Mail or Squirrel
Mail) are working with my Mail-Server.
 
Is it a general problem by using eXtremail?
Can anybody help me?
 
If you need I can send you a screenshot, next time.
 
Greets
 
Robert Walter