Originally Posted by kewa
Menu - Settings - then highlight your mail account. Scroll down to Outgoing Settings and tap on that then remove the tick from the box where it says Require sign in.
Sync your email then go back tick the box and add the login details.
I'd had exactly the same problem and this sorted it for me.
Hope this helps
I try that solution but unfortunately that doesnt work for me. Do you have some screenshots that you can share, i appreciate that.