Comment 4 for bug 1277493

I can confirm this too, specially problem with using ssmtp, cause no To: rewrite is possible there, i wrote a sendmail wrapper to fix it, some relays are unhappy with standard To: root and change i.e To: <email address hidden> which might break users mail filters.
I guess most people dont notice this cause using postfix/exim fixing the problem there, to make To: headers pretty