基於安全性的理由，可能會需要拒絕版本較舊的 Outlook 用 MAPI 的方式與 Exchange Server 連接。
1. Open a registry editor, such as Regedit.exe or Regedt32.exe.
2. Navigate to: HKLM\System\CurrentControlSet\Services\MSExchangeIS\ParametersSystem
3. Create a new String Value entry named Disable MAPI Clients.
4. Double-click the Disable MAPI Clients registry entry and set the value data to the level that you want. The list of values in the Value Data string represents the different ways that you can disable ranges of MAPI client versions.
For example, to prevent MAPI access completely, instead of specifying 0.0.0-65535.65535.65535", instead specify two ranges, so that the server components can log on, as follows: 0.0.0-5.9.9; 7.0.0-65535.65535.65535.
It is strongly recommended that you disallow all versions of Outlook with build numbers equal to or earlier than 5.3164.0.0 from connecting to Exchange Server.
5. Close the registry editor and restart the Microsoft Exchange Information Store service for the change to take effect.