ActiveSync is a synchronization program developed by Microsoft. It allows a mobile device to be synchronised with either a desktop PC, or a server running Microsoft Exchange Server or Kerio MailServer. Only Personal information manager (PIM) data (Email/Calendar/Contacts) may be synchronised with the Exchange Server. (Tasks may also be synchronised with Exchange Server on Windows Mobile 5.0 devices.) The PC synchronisation option, however, allows PIM synchronisation with Microsoft Outlook, along with Internet "favorites", files, and tasks, amongst other data types. Supported mobile devices include PDAs or Smartphones running Windows Mobile, or the Windows CE operating system, along with devices that don't use a Microsoft operating system[1], such as the Symbian platform. ActiveSync also provides for the manual transfer of files to a mobile device, along with limited backup/restore functionality, and the ability to install and uninstall mobile device applications.

Alternative software that allows mobile devices to synchronise non-Microsoft PIMs with a PC is also available; such as FinchSync[2] for Thunderbird, or Intellisync.

Starting with Windows Vista, the latest release of the Windows Operating System, ActiveSync has been replaced with the Windows Mobile Device Center

Release history

* ActiveSync 4.5 - microsoft.com

• Microsoft Office Outlook 2000 is not supported by ActiveSync 4.5.

• Conversion of database files for use on a mobile device is not supported by ActiveSync 4.5. 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. On previous versions, this feature was limited to devices running Windows Mobile software for Pocket PC 2003 and earlier.

• ActiveSync 4.2 - microsoft.com

• ActiveSync 4.1

• ActiveSync 4.0

o Build 4343 (RTM)
o Build 4358
ActiveSync 4.x no longer allow synchronization via exposed TCP/IP connections (such as WiFi, LAN or Dial-up). Wide Area synchronization is now only supported in conjunction with Microsoft Exchange Server under Windows Mobile devices. These changes have no effect on Personal Area synchronization such as Infrared, Serial, USB or Bluetooth. Also, ActiveSync 4.x only supports syncing with devices with Windows CE 3.0 and higher, and does not support Windows 9x or Windows NT 4.0 as the host operating system.

• ActiveSync 3.8 - HPC:Factor

• ActiveSync 3.7

o Version 3.7
o Version 3.7.1

• ActiveSync 3.6

• ActiveSync 3.5

o Build 1176
o Build 12007

• ActiveSync 3.1

o Build 9386
o Build 9439
o Build 9587

• ActiveSync 3.0