ActiveSync, being a Microsft product, is designed to work with MS Outlook.
If you want to sync email and contacts you basically need to have outlook.
You can still sync files and load programs etc without having outlook.
You need to set the Sync setting in AS not to sync email and contacts, if that's the way you want to go.
There are other programs that you can use to Sync your email and contacts but I have never used them.
One that springs to mind is
Finchsync, but I can offer no advice on how that works.