Han van den Bogaerde's site has excellent resources for Pegasus. There are a couple other abbreviated lists of Pegasus keyboard short cuts:

 http://short-keys.blogspot.com/2012/05/pegasus-mail-44-keyboard-shortcuts.html

And another abbreviated one here:

https://jr.co.il/training/pegasus-mail-keyboard-shortcuts.htm

I think Han's is the best.  http://www.vandenbogaerde.net/pegasusmail/pk_frame.html

Hi there,

is there a way to cancel sending a mail with a keyboard shortcut (same as clicking the little cross button on the lower right in the GUI)?

thx 

Not that I'm aware of.  A list of keyboard shortcuts can be found here:  

http://www.vandenbogaerde.net/pegasusmail/pk_frame.html