On previous versions, this feature was limited to devices running Windows Mobile software for Pocket PC 2003 and earlier. Conversion of font files for use on a mobile device is not supported by ActiveSync 4.5. Conversion of database files for use on a mobile device is not supported by ActiveSync 4.5. It is highly recommended that users upgrade to Microsoft® Outlook® 2003 messaging and collaboration client.

Microsoft® Outlook® 2000 is not supported by ActiveSync 4.5. Customers using Microsoft Exchange 2003 Service Pack 2 with devices running the Messaging and Security Feature Pack for Windows Mobile 5.0 will benefit from the following feature enhancements included in ActiveSync 4.5: Direct Push Technology, local device wipe, and certificate powered authentication to Microsoft Exchange. Remote PC Sync (via WiFi or LAN) has been removed due to Enterprise customer feedback around security issues. Faster file transfer speed and photo sync via Outlook are only available for Windows Mobile 5.0 powered devices.

Microsoft activesync 4.5 for win7