Re: PTR? what the heck is it?

From: Walter Roberson (roberson_at_ibd.nrc-cnrc.gc.ca)
Date: 06/09/03 

Date: 9 Jun 2003 18:10:36 GMT

In article <mt2Fa.27375$6f3.4869749@news1.telusplanet.net>,
John Joot <johnjoot@hotmail.com> wrote:
:thnks for the info barry...the reason why i'm asking is this... in my mail
:server program, among the options, for security purposes, i am given the
:following to check-mark:

:what i don't understand is if there is already a reverse lookup on PTR and
:shutting down option checked, why would i need to check-mark (2) (3) (4)
:a&b?

The PTR lookup of the first option refers to the information available
about the machine that made the connection. The other options refer
to the information available about the addresses claimed within the
mail protocol. The mail -protocol- doesn't care if a machine
belonging to (say) telusplanet.net tries to send a message
purporting to be from a user at (say) JohnJootHatesGaldiolas.org,
but the fact that that doesn't exist can be detected at various
points. 

-- 
Aleph sub {Aleph sub null} little, Aleph sub {Aleph sub one} little,
Aleph sub {Aleph sub two} little infinities...