Hi,
Is it possible in Linux to restrict POP3 or IMAP for some users.
I need a confirmation on this, that it is possible or not.
Please reply

It's a computer. You can make it do just about anything. Why, in particular, do you need confirmation of that fact?

Yes, it is possible. Can be done in many ways including within an MTA (Mail Transport Agent) such as sendmail or postfix. For example, here is a webpage which discusses how to implement postfix restrictions

I have to ask.
Why do we have to be testy, smart mouthed when someone asks a legitimate question?
He was very clear in his question.
Maybe he didn't word it like you think he should but he did ask for help with a legitimate problem he is/was having.
Maybe a minor problem to you and the rest of us but that's why he asked for help hoping that someone with the knowledge would share.

As I read the faq on how to post questions, I dodn't see where grammar would be graded.

In the future, please consider sending these kind of messages directly via email, instead of steering the thread off topic. FWIW, I too found ravis007's post to be rather curious, and I think I understand where choogendyk was coming from. Usually people will ask for help performing a certain task, and not just whether it's possible or not. Given the unusual request, I don't see how choogendyk's asking for clarification could be described the way you did. Hopefully, ravis007 will indeed post a follow-up and clear up some of the doubts which I'm sure many of us have regarding his post.