[Dovecot] Loading messages

[Gabriel Granger]

Thanks to all for pointing out the Thunderbird bug workaround, I've got 
another question

Some of my users are complaining that when they select a message, the 
email client says "Loading Message" and either takes a long time to 
display a small message or does not display the message at all.  Its 
odd becuase it seems that larger message on these users machines seem 
to open more quickly then the small 1Kb - 15Kb messages.   Looking a 
little further on the messages that wont open they all seem to be very 
small in size.  Is this a common issue? or something i need to tweak on 
the dovecot.conf or on the client side?

Gabe