IMAP and meeting invitations

Hi everyone,

at first I thought it is a straight bug in kmail that some (actually most of 
the) meeting invitations from my co-workers do not get displayed inline, but 
instead as "meeting.ics" attachments. If I open these attachments in kontact 
the meeting is not added to my calendar and the person who scheduled the 
meeting does not get a reply. If I press "v" to view the source code of the 
mail, the invitation suddenly gets displayed inline.

After some diggin' I found out that it has actually to do with on demand 
attachment loading. If I turn it off in the IMAP account settings the 
invitations is displayed inline when I select the mail.

It seems to me that the size of the attachment/mail matters. An invitation 
with only four attendees gets displayed inline, while another one with five 
doesn't. Difference between them in bytes is just ~250, but the bigger one is 
over 5000 bytes. Is there a magic threshold around 5k where the on demand 
loading kicks in?

Is there a way to force fetching/display of text/calendar mime parts? I was 
thinking about developing a patch that adds an exception for meeting 
invitations. Any ideas where to look to get started?

Regards
Heiko