Here's my setup in Claws 3.0.2 Account Preferences

Basic :
Protocol IMAP
receiving : imap.gmail.com
SMTP : smtp.gmail.com

Receive :
IMAP4
Authentication method : Automatic
all boxes checked below

Send :
Authentication
SMTP AUTH checked
Method : LOGIN
gmail username and password

SSL
Use SSL for IMAP4 connection
Send : Use STARTTLS command
Use non blocking checked

Advanced :
SMTP Port 587
IMAP4 Port : 993
nothing else checked.

With these settings I'm able to send and receive mail from my IMAP Gmail account. Every so often I'll have to open a message twice before it will fetch from the server. Has anyone come up with a way to implement a 'move to' button to emulate moving a mail to the all mail folder in GMail. Sort of an archive button? I can click hold and drag a message to the all mail folder, but a button would be nice.