Unable to read / capture emails from Redhat (Linux) system to our POP3 server

Question

Hi All,
I am facing some problem while capturing the Email from Redhat (Linux) system. Let me explain the process.
We have a windows service which receives all the Emails to it and process the attachments. We use the "Pop3MailClient"  to create the Email object.
However the problem is now we can not track the Email from a Redhat(linux) system , but the same email if we forwarded from our Microsoft Out look express it works fine.
Please suggest me as soon as possible, what necessary steps I need to take.
Waiting for your valuable reply.