Earlier today I was bitten by something that has irritated be before as
well.  When reporting bugs from an "emacs -Q", emacs doesn't know my
email address.  No problem, I can edit the From: header.

However, I like to use my local sendmail as transport, because I have
already told that how and where to forward my mail, and it seems like a
perfectly good option.  But message.el then decides to make up its own
envelope-from, regardless of From: header.  That makes the mail bounce.

Attached is a patch to emacsbug.el that checks if what message.el would
do results in a bogus address, and if so, defaults to the From: header
instead.

(This is my first patch submission, let me know if it should be done
differently.  Copyright paperwork is on file since ages ago.)

...Peder...
-- 
I wish a new life awaited _me_ in some off-world colony.