ID: q160691
The information in this article applies to:
With Microsoft Commercial Internet System (MCIS) 1.0, multiple HELO and EHLO commands may not parse and route correctly. If the responses are rejected as invalid, the multiple 200 level commands may cause the MCIS Internet Mail Server (IMS) to return a 599 error.
Upgrade your IMS servers to MCIS Service Pack 1 (SP1). This will update the Smtpsvc.dll file and correct the problem.
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 : WINNT:1.0
Platform : winnt
Issue type : kbbug
Solution Type : kbfix
Last Reviewed: November 20, 1998