T 5.73 Impersonation of a sender

It is relatively easy to impersonate senders when dispatching e-mail. This might result in damage if the recipient considers the information contained in the e-mail to be authentic and binding.

Example:

The commonly used Eudora mail program allows mail with an incorrectly specified sender to be forwarded to a mail server without a password check. If user authentication has not been performed, this mail is only identified as "Unverified" in the field labelled "X-Sender". However, experience has shown that very few recipients pay attention to this. Besides, most mail programs do not include this field in their standard configuration.