SMTP Banner Has Been Customized

[This topic is intended to address a specific issue called out by the Exchange Server Analyzer Tool. You should apply it only to systems that have had the Exchange Server Analyzer Tool run against them and are experiencing that specific issue. The Exchange Server Analyzer Tool, available as a free download, remotely collects configuration data from each server in the topology and automatically analyzes the data. The resulting report details important configuration issues, potential problems, and nondefault product settings. By following these recommendations, you can achieve better performance, scalability, reliability, and uptime. For more information about the tool or to download the latest versions, see "Microsoft Exchange Analyzers" at]  

Topic Last Modified: 2006-05-17

The Microsoft® Exchange Server Analyzer Tool tries to send a message to the Postmaster account or a user-defined account for the Simple Mail Transfer Protocol (SMTP) domain. The Exchange Server Analyzer displays a warning if it receives a response from that account different from the following default response:

"220 Computer Name . Domain Name .com Microsoft ESMTP MAIL Service, Version: Version Number ready at Date Time +0000"

This warning indicates that the default response that appears when the program connects to an Exchange SMTP virtual server has been customized.

A customized SMTP banner may not be an issue if the Exchange Server administrator has intentionally changed the banner as described in Microsoft Knowledge Base article 281224, "XCON: How to Modify the SMTP Banner" (

If the default SMTP banner has not been intentionally customized by the Exchange Server administrator, this warning may indicate that the Exchange Server is behind a Firewall or SMTP Proxy that is filtering the Exchange Server Extended SMPT (ESMTP) commands.

If Exchange Server ESMTP commands are filtered, this can have a significant effect on Exchange performance and may produce the behavior described in Microsoft Knowledge Base article 320027, "Cannot send or receive e-mail messages behind a Cisco PIX firewall" (

For more information about customized SMTP banners see the following Microsoft Knowledge Base articles:


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