The device can allow and tag the e-mail if the message sender
is detected as a spammer. This tagging can occur at the connection
level so that all the e-mails for the connection in question are tagged.
Otherwise, you can tag only an individual e-mail. Two tagging methods
are supported:
Tag the subject: A user-defined string is added at the
beginning of the subject of the e-mail.
Tag the header: A user-defined string is added to the
e-mail header.
