we have two types of users in our company,they are
advanced users- they have both internal and external email facility.
normal user- only have an internal email. (no access to the outside from compny)
we are using one domain for both internal mails and external mails. Only certain people have external mail accounts (advanced users). those who do not have external email facility (normal user) shouldn't be able to access their emails over web mail or outlook express from the outside in our company.
I have configured mailscanner to block smtp of normal users and they are not able to send emails over web mail or outlook express from the outside of our compny (apart from our internal IP range).
but advanced users can send or receive emails from both sides.(internal/external any IP range)
But im struggling to block receiving emails (pop3) by normal users and I need to stop pop3 for normal users when they trying to get emails from the outside of company.
simply if they try to access emails from a different IP other than our internal IP range, that messages should not be received. But when they are in our internal IP range they should able to send and receive emails.
think our internal IP range - 192.168.0.0/16
if normal user try to get email from a different IP range (eg:- 18.104.22.168) it needs to be blocked.
I can do this easily by using 2 domains like 1 domain for internal access and other one for external access. but I need to do this by using only a one domain.
request you kind help to solve this problem.
thanks in advanced