- The Mailbox server role is enabled in Exchange Server 2013.
- Exchange mailboxes use extended MAPI to communicate with the Exchange Server.
- The extended MAPI uses Microsoft RPC over HTTP (remote procedure call over HTTP) protocol.
- Many clients (such as mobile devices) are dropping connections to the Exchange Server.
In this scenario, the CPU usage on the Exchange server may reach 100 percent.
Hotfix informationImportant Do not install a language pack after you install this hotfix. If you do, the language-specific changes in the hotfix will not be applied, and you will have to reinstall the hotfix. For more information, see Add language packs to Windows.
A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem.
If the hotfix is available for download, there is a "Hotfix Download Available" section at the top of this Knowledge Base article. If this section does not appear, submit a request to Microsoft Customer Service and Support to obtain the hotfix.
Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft website: Note The "Hotfix Download Available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.