Update so far: Using Thunderbird I am able to connect properly and send email on my GMail account. It finds and autoconfigures all settings. On Evolution it doesn't.
I can recieve mail on both Thunderbird and Evolution.
Regarding my own server Thunderbird reports that the password/username is incorrect while I know I've entered them correctly and this cannot even connect. On Evoloution I can connect and recieve mail but not send.
/Martin S