ID: q168108
The information in this article applies to:
This article applies to Microsoft Mail Server. The Internet Mail Server may process mail slowly resulting in a backup of mail in the mail queue as well as in the pickup directories. The queue directory will contain a large number of .rtr files which indicates that multiple Domain Name Service (DNS) retries have occurred.
Excessive DNS query failures cause mail processing to perform slowly because IMS continually attempts to resolve the names against the DNS. The DNS lookup attempts use a critical section to ensure mutual exclusion when running the DNS lookup code. This causes all other queue processing that requires DNS resolution to stop until the current DNS lookup is complete.
Smtpsvc.dll was modified to resolve contributing issues with the handling of DNS MX lookups, and the handling of DNS lookup retries.
Microsoft has confirmed this to be a problem in Microsoft Commercial Internet System version 1.0. This problem has been corrected in the latest U.S. Service Pack for Microsoft Commercial Internet System version 1.0. For information on obtaining the Service Pack, query on the following article in the Microsoft Knowledge Base:
ARTICLE-ID: Q183062
TITLE : MCIS 1.0 Service Packs 1 and 2 Information
Version : 1.0
Platform : winnt
Hardware : ALPHA x86
Issue type : kbbug
Solution Type : kbfixLast Reviewed: November 20, 1998