How about setting up an inbox (e.g. pleaseforward at spamgourmet.com) for emails that are to be sent from an sg address? You could define rules for e.g. the first two lines of the body to specify where it should go to and where it should come from. This would avoid having to log into the website, the copying and pasting etc. Any problems with the 'to' or 'from' and the mail could be returned to inform the sender.
I'm sure this has been suggested before, but i did do a quick search... nevertheless, I'll indulge myself with a