AFAIK, you can't. Just by adding PGP over the content of the mail and comparing it to the sender's signature.
The SMTP server can ask the user for auth. but you can't know that. Regards, Lior Kaplan [EMAIL PROTECTED] http://www.Guides.co.il Come to write at the forums: http://www.guides.co.il/forums ----- Original Message ----- From: "Moshe Kaminsky" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Thursday, September 25, 2003 8:33 PM Subject: mail origin verification > Hi, > > I was wondering, how can I verify that an email really arrived from > where it claims? For example, how does the mailing list program know > that this mail really came from me? I saw nothing in the headers that > allows it. > > Thanks, > Moshe > > -- > Moshe Kaminsky <[EMAIL PROTECTED]> > Home: 08-9456841 > > > ================================================================= > To unsubscribe, send mail to [EMAIL PROTECTED] with > the word "unsubscribe" in the message body, e.g., run the command > echo unsubscribe | mail [EMAIL PROTECTED] > > > > ================================================================= To unsubscribe, send mail to [EMAIL PROTECTED] with the word "unsubscribe" in the message body, e.g., run the command echo unsubscribe | mail [EMAIL PROTECTED]
