Isn't it more of a domain restriction than a user restriction?  I close the
realyin on mydomain.com, you telnet to my box and try to send to somwhere
other than mydomain.com and you're restricted.  I could easily be wrong.

J

-----Original Message-----
From: Kevin Miller [mailto:[EMAIL PROTECTED]] 
Sent: Friday, November 16, 2001 11:59 PM
To: MS-Exchange Admin Issues
Subject: RE: Relaying - background?


Non open Relaying requires a user to login to the server, have an account on
the server and have rights to that account. So only Joe can send email from
Joe, when Joe is logged in as Joe. The other method is to restrict based on
Ip so Joe can only send email if he lives on a 10.0.0.x ip range else he
can't sent nothing.

Open relay means the server does not care it will send anything from anyone.
Joe can send messages from sally to anyone he wants to. The server is purely
a MTA. 

Does that help?

Kevinm M WLKMMAS, UCC+WCA, CKWSE


-----Original Message-----
From: Bob Peitzke [mailto:[EMAIL PROTECTED]] 
Sent: Friday, November 16, 2001 2:09 PM
To: MS-Exchange Admin Issues
Subject: Relaying - background?


Recently one of my users forwarded me a couple of NDR messages she got,
containing stuff like "recipient name is not recognized", "550", "Relaying
denied", "user unknown".  Our Exchange 5.5/SP3 server is not an open relay,
and we are cool with all the ORDB & ~ databases, FWIW.

This got me wondering about how relaying really works.  I know that incoming
mail destined for addresses in our domain go to our server, identified by
the MX record in our ISP's DNS tables.  I know that outgoing mail from our
server goes to a mail server at our ISP, which forwards it to other servers
in the appropriate domains - but I don't know how our server knows which
mail server at our ISP to send stuff to. Our IMS is set up to use DNS for
message delivery, not to forward to a specific host.

Another part I don't understand is how SPAM works - if our server was an
open relay, how would a spammer send messages to our server, but have them
addressed to recipients in a different domain?  I.e. where is the separate
information on mail server to send to and ultimate recipient?

I've dug around some in Technet and various knowledge bases, but haven't
been able to find any illuminating background on how relaying and spamming
works.  I'd love to read up on it, if anyone has a pointer to a relevant
article.

TIA & have a nice weekend!

Bob Peitzke


List Charter and FAQ at:
http://www.sunbelt-software.com/exchange_list_charter.htm


List Charter and FAQ at:
http://www.sunbelt-software.com/exchange_list_charter.htm

List Charter and FAQ at:
http://www.sunbelt-software.com/exchange_list_charter.htm

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