http://www.syncdata.it/

In addition to IntelliSync, SyncExpress is the most important suite that offers the capability of synchronizing with Outlook Express on the desktop. The new, greatly upgraded version has just been released and has the following features:

• Synchronize Address Book with Pocket Outlook Contacts
• Synchronize Outlook Express Inbox with Pocket Outlook Inbox
• NEW! Store Pocket Outlook messages in a separate account- you can now synchronize Outlook with a PC and Outlook Express with a second PC!
• NEW! Folder based filter for synchronized contacts
• NEW! Windows Mobile 5 Pocket PC support
• NEW! Localized in 5 languanges

It's available here and costs $17.95. I will post a complete test report and one-on-one comparison to IntelliSync some time.