[index] [text page] [<<start] [<prev] [next>] [last>>]
Page 68: Some points about SMTP
It's useful for me to be able to send email from fanf2@cam.ac.uk from
anywhere (e.g. when I'm travelling) but that also means anyone else
can masquerade as me.
.forward files rely on this feature -- email coming out of Hermes is
frequently not from Hermes users, but was to Hermes users who are
forwarding it elsewhere.
SMTP's multi-hop nature is also helpful for dial-up connectivity
and communicating through firewalls.
If a forged message can't be delivered then it will be returned to
the innocent third party. This is "collateral spam", and is nowadays
mainly caused by viruses (since there are now so many viruses).
Double bounces are usually ignored by large sites, which implies
an increased risk of losing real email.
SMTP's fast-and-loose design has advantages but makes it easy to abuse.
Generated by MagicPoint