It's not the envelope, it's only the "To:" header modified, it's a filter bypass technique.
> Where is are you seeing this undisclosed recipient in the to field? In > you client, or in your mail servers log files? > > > On Tue, 2008-01-08 at 11:12 +0100, Info Neoblu wrote: >> >> > -----Messaggio originale----- >> > Da: Shane Chrisp [mailto:[EMAIL PROTECTED] >> > Inviato: martedì 8 gennaio 2008 11.00 >> > A: toaster@shupp.org >> > Oggetto: Re: [toaster] Info for send mail >> > >> > That sounds like a problem with the mail client rather than the >> server. >> > âUndisclosed Recipient:;â is pretty normal for mailouts from >> clients >> > such as outlook express etc. >> > >> This happens on different clients Outlook, Outlook Express, Thunderbird >> .... with different versions. >> > >
