Anti-spam for Microsoft Server Exchange

[Lebon14]

Hi guys

I'm searching for an anti-spam software for Microsoft Server Exchange (to use with Microsoft Outlook 2003). A free and efficient will do the job or if it needs to be paid for, we have a very small budget (like 200-300$ CAD for 25 or so computers).

Thanks for you help

P.S : 22 WinXP and 3 WinVista.
P.S2 : NOT POP3!

 

[z3r010]

The only effective exchange antispam solution I ever found was GFI but it's a premium product

 

[Lebon14]

^ On top of all, it's only on a server... oh well, it looks good though. I'll be taking procedures to see if it's OK.