GoFuckYourself.com - Adult Webmaster Forum - View Single Post - E-mail header experts, where is this mail from?

rowan · 05-24-2006, 06:18 AM

In general you cannot trust SMTP headers, apart from the ones that the receiving system creates (assuming you do trust that

)

This means that the only IP which is pretty much guaranteed to be accurate is the one that your server marks as delivering the mail. Anything else, including lines like

Received: from [80.87.84.30] by web35905.mail.mud.yahoo.com via HTTP; Tue, 23 May 2006 11:48:56 PDT

... can be forged.

05-24-2006, 06:18 AM
rowan Too lazy to set a custom title Join Date: Mar 2002 Location: Australia Posts: 17,393	In general you cannot trust SMTP headers, apart from the ones that the receiving system creates (assuming you do trust that ) This means that the only IP which is pretty much guaranteed to be accurate is the one that your server marks as delivering the mail. Anything else, including lines like Received: from [80.87.84.30] by web35905.mail.mud.yahoo.com via HTTP; Tue, 23 May 2006 11:48:56 PDT ... can be forged.