Error message when you use ActiveSync to synchronize a Windows Mobile-based device to Exchange 2003: "0x85030027 -- The Exchange Server requires certificates to log on"

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Article ID: 927467 - View products that this article applies to.
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When you use ActiveSync to synchronize a Microsoft Windows Mobile-based mobile device to Microsoft Exchange Server 2003, you receive the following error message:
0x85030027 -- The Exchange Server requires certificates to log on. Connect your device to your PC on the corporate network to obtain a certificate.


This problem occurs if the following conditions are true:
  • You have not enabled certificate-based authentication for Exchange ActiveSync.
  • The Ignore Client Certificates option under the Client certificates setting is not enabled in the Iisadmpwd virtual directory.


To resolve this problem, configure the Client certificates setting in the Iisadmpwd virtual directory to Ignore client certificates. To do this, follow these steps:
  1. Start Internet Information Services (IIS) Manager.
  2. Expand Server_Name (local computer), expand Web Sites, and then expand Default Web Site.
  3. Right-click Iisadmpwd, and then click Properties.
  4. On the Directory Security tab, click Edit under Secure Communications.
  5. Under Client certificates, click Ignore client certificates, and then click OK two times.
Note This is the default configuration.


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Visit our Windows Phone Forums for more helpful hints and ideas.


Article ID: 927467 - Last Review: November 10, 2011 - Revision: 2.1
  • Microsoft Exchange Server 2003 Enterprise Edition
  • Microsoft Exchange Server 2003 Standard Edition
  • Microsoft ActiveSync 4.5
  • Windows Mobile 6.5 Standard
  • Windows Phone 7 Consumer
kberrmsg kbexchmobility kbexpertiseadvanced kbtshoot kbprb kbwp7 kbwindowsphone7 KB927467

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