XFOR: Performance with Site-wide Distribution List Expansions

SYMPTOMS

The store procedures for distribution list processing need to improve performance with site-wide Distribution List expansions. Current expansion times for a 5,000,000-user site are 23 hours, which is 13 hours longer than the maximum timeout setting for the client-side SQL DLLs. As such, the query times out on the client (SMTP server) and Abookdb.dll closes the connection. The computer running SQL Server then attempts to return the result set of the query and cannot, creating an error log message for a broken pipe.