Mac Mail disconnects from OS X Mail Server

[ScottN]

Hi, I'm new to managing an OS X network, and we're having some issues with a couple workstations. One is an iMac the other is a MacBook (Both Snow Leopard). Both have Mail configured to connect via IMAP to the in-office OS X (Tiger) server.

The issue is: Both computers randomly disconnect from the mail server. There are 3 others (Snow Leopard) that are working with NO issues. I've checked DNS, I've compared settings, nothing.

On top of the mail issue, they also intermittently drop their mounted network shares.

Can anyone point me in the right direction? All my searching yields are loads of poeple having issues connecting to Windows Servers, but none for OS X server.

Thanks,

Scott