I just wanted to add to my last note about -V -n doubling output.. If you don't specify -V, there is no output whatsoever.
How about a 'hash' like ftp? Just print a . without a newline for each email address done. I wasn't sure if it was actually doing anything - and on large domains it could look like it's hung up (or, if it WERE to hang, you wouldn't know it). Rick