mail server / name server issue

[jfall]

I have a mail server running.. i'm using sendmail... the incoming/outgoing mail servers are mail.domainname.com .. I am trying to send/receive mail with the pop account from a windowsxp computer which I have networked to my linux computer. I can receive mail fine, but when I try to send it says "Relaying denied, IP name lookup failed 192.168.10.1" .. so i'm guessing it is having trouble looking up my internal IP address of my windows computer.. anyone know what I can do to fix this?

[fancypiper]

I used Suresh Ramasubramanian's email guide (http://www.hserus.net/dlhowto.html) to set up mine with no problems.

Common e-mail tools:
sendmail (http://www.sendmail.net/) - postfix (http://www.postfix.org/) - sends mail to local users (and internet when configured correctly)
fetchmail (http://www.tuxedo.org/~esr/fetchmail/) - gets mail from internet pop accounts
procmail (http://www.procmail.org/) - sorts and delivers into separate mailboxes
mutt (http://www.mutt.org/) - mail client that sucks less than all the others
Email the Linux Way (http://www.mandrakeuser.org/docs/connect/index.html#mtuw)
Suresh Ramasubramanian's email guide (http://www.hserus.net/dlhowto.html)
The Linux Mail User HOWTO (http://www.tldp.org/HOWTO/Mail-User-HOWTO/index.html)
The Linux Electronic Mail Administrator HOWTO (http://www.tldp.org/HOWTO/Mail-Administrator-HOWTO.html)
Gotmail (http://ssl.usu.edu/paul/gotmail/), a utility to download mail from Hotmail accounts