Exchange and Apple's Mail

Hi,

Recently I had to migrate from a Unix based email system to an Ms Exchange based email system here at work.  Although the IT folks here recommend WebMail and MS Outlook, I prefer to stick with Apple Mail.  The problem is, that I have to quit from Mail and go back to it again to get my email.  This worked flawlessly with the Unix based email system.  I wonder if anyone else has this problem.  My OS is 10.6.8 here and Mail is 4.5.

Thanks ahead,

János