weird smtp problem with Kontact

Hi There,

I setup my smtp server in Kontact and when it’s trying to send messages, the status bar goes to like 94%, 99% or XX% and gets stuck before i get an error saying

Sending failed:
The message will stay in the 'outbox' folder until you either fix the problem (e.g. a broken address) or remove the message from the 'outbox' folder.
The following transport was used:

I’m 100% sure it’s the right settings (uname&passwd) and i’ve also tried different servers…no luck tho…by chance it sometimes sends an email off but then next time, it gets stuck with the same error again. What’s going wrong here?
Thanks for any hints or suggestions!

Also I can set this same mail account up in Thunderbird and it sends emails just fine. But I would like to stay with Kontact. How do I get emails sent? :o I have used Kontact before (then I relocated - got a new ISP - and i can’t use it anymore???:’() There must be a way to fix this… Any clues?