problems with entourage and exchange

Running office for mac 10.4 using Entourage and Exchange 2003.

Users send e-mail via entourage and e-mail is not being received. What log
files can i use on server to see if mail is being sent/received properly
for
Entourage.

Web e-mail works fine, so network is okay. Suspect problems with Entourage
and Exchange compatibility.

Is Entourage more reliable on exchange 2007 and Office for mac 2008?

thanks