Spammers Most Likely Users Of E-Mail Authentication (TechWeb)

Spammers Most Likely Users Of E-Mail Authentication (TechWeb)

Most whitelisting is on the Internet message "From:" header, not on the SMTP "MAIL FROM:" header. Thus, you tend not to break whitelists, but you do ensure that anything that harvests your "From:" header for spamming doesn't trigger bounces back to you, as you know that that address never accepts bounces.