unsubscribe.rb:10:in `unsubscribe!': Couldn't process your unsubscribe
request. Please try sending it to ruby-talk-ctl@ruby-lang.org instead.
(IncorrectMailAddress)
from unsubscribe.rb:14:in `do_unsubscribe'
from unsubscribe.rb:20:in `process_mails'
from unsubscribe.rb:23:in `<main>'