When you try to make a telephone call to another user by using Microsoft Windows Messenger, the following information appears: You receive this message even though Windows Messenger does not actually try to dial the number.

This issue occurs if the telephone number of the user who you want to call is entered incorrectly in the Active Directory directory service. When an administrator enters a telephone number for a user account in Active Directory Users and Computers, the administrator can enter the telephone number in any format. However, Windows Messenger expects a space character to appear between the country code and the remainder of the telephone number. One example of how to correctly enter a telephone number is "+1 (425)5550151."

When Windows Messenger tries to make a telephone call to a contact in your Contacts list, Windows Messenger dials the telephone number from your contact's presence document. This telephone number appears for your contact in Active Directory. If there is no space character after the country code in the telephone number, Windows Messenger interprets the whole telephone number as the country code and cannot dial the number.

The error message that is described in the "Symptoms" section of this article is also displayed if the server cannot route to the Internet Protocol-Public Switch Telephone Network (IP-PSTN) gateway to make the call.

To resolve this issue, use Active Directory Users and Computers to insert a space after the country code in the telephone number of the user who you want to call. To do this, follow these steps:

1. Start Active Directory Users and Computers.
2. Locate and right-click the user whose telephone number you want to modify, and then click Properties.
3. Click the General tab, edit the telephone number, click Apply, and then click OK.
4. When you have finished modifying the telephone numbers, stop, and then restart Microsoft Office Live Communications Server 2003.

If the error message still occurs, make sure the server is successfully routing to the IP-PSTN gateway.

When you configure an IP-PSTN gateway on Live Communications Server 2003 to enable computer-to-telephone calling, make sure that you enter telephone numbers in a format that the gateway can interpret and dial. For additional information about how to configure Live Communications Server 2003 to interact with an IP-PSTN gateway, see "Appendix A — Setting Up IP-PSTN Connectivity" in the Microsoft Office Live Communications Server 2003 Reference Guide. This guide is located in the Documentation folder on the Live Communications Server 2003 CD. See the documentation for your particular IP-PSTN gateway for more information about which formats the gateway will accept.