XCON: Internet Mail Service Does Not Respond if Recipient Does Not Have an Address Type

The Exchange Server Internet Mail Service may stop responding or "crash" after attempting to deliver a message to an Exchange Server custom recipient that was created by using Lightweight Directory Access Protocol (LDAP).

This issue can occur if one of the recipients in the message has a missing address type in its X.400 address. For example, the address is displayed as follows in the Exchange Administrator program: Using a custom-made program that uses LDAP to create the recipient created the preceding address. The address should look like the following address: The missing address type causes the issue with the Internet Mail Service.

To resolve this problem, obtain the latest service pack for Exchange Server 5.5. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

To work around this issue as an alternative to applying this fix, ensure that any recipients that are created outside of the Exchange Server Administrator program have correct address types in their proxy addresses.

Microsoft has confirmed that this is a problem in Microsoft Exchange Server version 5.5. This problem was first corrected in Exchange Server 5.5 Service Pack 4.