The most tedious part of setting up for me was editing/translating all the messages (with something like ArkEditor it takes a long while to load the page), so I’m not keen to go back and add a signature block at the end of each one.
I think it would be great if there was a separate field where you could input your company/club/whatever signature block that would be inserted into all the e-mails. It would also be useful if you do some re-branding later.