dovecot - Jan 2011 - email addresses as usernames with Kerberos

Hi,

I was trying out Kerberos authentication with som sample users for 
Dovecot and stumbled into this problem:

The user names are of the form local-part at domain, so the Kerberos 
principal becomes "local-part\@domain at REALM".

But it seems Dovecot (1.2.9) doesn't understand that syntax.
Looking at the 2.0.8 sources I guess it's not supported.

But isn't this a valid Kerberos principal?
Is it a bug, or a missing feature or is there a special reason for not 
supporting it ?

kind regards,
Peter