Sending mail within domain only

I would like to add restrictions to some email address and IP addresses that they can only send email within the domain, and not to outside world. we have a copier which can scan to email right from the machine which i want to restrict so it can only send email internally. How can I accomplish this?

Thank you

can you not configure the copier to scan to LAN ftp folder only? that seems actually better.
Usually those multi-functional machines in the network have an IP which can be restricted.
For that machines IP you can make firewall rules for instance, but I would look at the configuration on the copier itself.

it does scan to the folder as well, but people are lazy, maybe i’ll just disable the whole function in the machine. What about some users, how can i restrict some users so they can not send email outside of the domain?

Thank you

in our company we have 9000+ users. we cant have them email scanned documents all the time. so we use ftp to a shared drive.

as for resticting users to email to the world… I don’t really know, I guess it depends on the mail server.
Per haps some firewall rules will help. IP source to IP destination

There has to be a way to restrict as per user, rather than IP, what if that person logs on from another computer.

Per haps it is possible when you use LDAP, I believe it depends on your mailserver.
if you use postfix, look in webmin - Servers - Postfix Mail Server and click smtp client restrictions.