Help - mail server how to.

Hello,
Is there a 2003 web server manual online? Particularly for mail server
setup, just purchased a Windows 2003 Web Server from One and One.

I am trying to get the mail server to work, and to be honest I haven't a
clue where to start.

If you have the time, I would appreciate any suggestions.

I have made sure of the following:

- Primary MX record points at our web server.
- POP 3 Service installed, 2 mailboxes added under our primary domain.
- IP filter, not sure how this works but I think I have allowed both PORTS
25 and 110 in and out. (is this safe?)

When I send an email, I receive the following error:
reason: 550 Unknown local part Gary in <gary@newwebserver.com>

Any help greatly appreciated!

Thanks,

Gary/

Some more information:

I am trying to establish the steps I need to take in order to have a mail
server working.
Email server setup:

1 - Create an MX record and point it to <SERVER01>
2 - Configure IP filter to allow PORT 25 / 110 in and out
3 - Create a new domain in the POP SERVICE
4 - Add mailboxes to the domain recently created in the POP SERVICE

I think I have done all of the above, but when I send an email I get an
error returned:
----- The following addresses had permanent fatal errors -----
gary@server.co.uk
(reason: 550 Unknown local part gary in gary@server.co.uk)
----- Transcript of session follows -----
.... while talking to mx01.server.co.uk.:
>>> RCPT To:gary@server.co.uk
<<< 550 Unknown local part gary in <gary@server.co.uk> 550 5.1.1
<gary@server.co.uk>... User unknown



Any help greatly appreciated!



Thanks,



Gary.