Sending mail fails

[Martijn Kluijtmans]

Since version 0.8 of Mozilla, I'm sometimes unable to send my mail 
through smtp.
I don't  know when this happends, it seems to me this error occurs 
randomly (with or without attachments,..). When I write a message, I 
click on the send button. I can see that some data is being transfered, 
but then Mozilla hangs.
This happens to Mozilla 0.92, 0.91, 0.9 and 0.81. With 0.8 I never have 
this problem.

Anyone knows what the problem can be?

Martijn