MS Exchange or SMTP Very Slow w/ Proxy Packet Filtering Enabled

The information in this article applies to:

• Microsoft Proxy Server version 2.0

SYMPTOMS

Microsoft Exchange Server or other third-party SMTP servers may act sluggish or very slow when you install them on the Proxy Server version 2.0 computer with packet filtering selected (enabled). The mail delivery to and from the Internet may take several minutes or fail completely.

CAUSE

The packet filtering feature of Proxy Server 2.0 may be blocking the Identification Protocol (Identd) requests from the Internet. Some mail servers try to use the Identd protocol to identify other mail servers on the Internet.

RESOLUTION

The predefined filter for Identd needs to be added.

1. Open the Winsock Proxy Service Properties and select the Service tab.

2. Under the Shared Services section, select Security, and choose Add.

3. Select the Identd filter from the list of predefined filters. This will allow Identd traffic to pass through instead of being discarded by the proxy packet filter driver.

MORE INFORMATION

More information on the IdentD (Ident or Ident) protocol can be found on the Internet in RFC 1413.