On 10/21/2016 10:41 AM, Paweł Grzesik wrote: >> DATA >> 354 End data with <CR><LF>.<CR><LF> >> From: j...@mailtest.example.com > <mailto:j...@mailtest.example.com> <mailto:j...@mailtest.example.com > <mailto:j...@mailtest.example.com>> >> To: pa...@mailtest.example.com > <mailto:pa...@mailtest.example.com> <mailto:pa...@mailtest.example.com > <mailto:pa...@mailtest.example.com>> >> Subject: Testing SCAM >> Text: ABC123 >> . >> 250 2.0.0 Ok: queued as 481D6C76B6 > > But I'm talking about this part. So here we have DATA where I can > type From:, To: and Subject: then message and e-mail will go > from the "From:" instead of the one from the header "MAIL FROM:". > > The problem is that most of the e-mail clients will show that From > in the From. I'm not sure if there is a way to block it? Or I'm > missing something?
Yes, most *mail clients* will display the From: header rather than the envelope sender. Additionally, if you reply to the message, the *mail client* will reply to the From: header rather than the envelope sender. First note different envelope sender and From: header isn't a postfix issue; it's how email is designed to work. Next note that it's the mail client that chooses to display the From: header rather than the envelope sender; this is the accepted behavior across virtually all mail clients. Nothing prevents the mail client from displaying the envelope sender (usually found in the Return-Path: pseudo-header after delivery), but few (none?) of them chose to do so. Probably because most end users would find it confusing. That's how email works, and it's a useful feature used by mailing lists, remailers, automated notification systems, etc. Yes, unfortunately some abuse this feature. If we disable every feature that might be abused, we're left with nothing. -- Noel Jones
