Event ID 4000 and Messages Are Not Delivered As Expected When You Use IIS 5.0 SMTP Service As Relay Host

When you use the Microsoft Internet Information Services (IIS) 5.0 Simple Mail Transfer Protocol (SMTP) service to relay messages to Microsoft Exchange Server 5.5 or other SMTP mailers, you may find that some messages take a long time to deliver and some messages are not delivered at all. Additionally, the following event is logged in the Event Viewer:

This behavior occurs because the Exchange Server 5.5 Internet Mail Service does not support the 8bitmime Extended Simple Mail Transfer Protocol (ESMTP) verb.

To resolve this behavior, use the MetaEdit 2.2 utility to turn off support for the 8bitmime ESMTP verb in IIS. To do so, follow these steps:

1. Download and install the MetaEdit 2.2 utility.
   
2. Click Start, point to Programs, point to Administrative Tools, and then click MetaEdit 2.2.
3. Expand LM, expand SmtpSvc, and then expand 1.
4. In the right pane, double-click SmtpInboundCommandSupportOptions.
5. In the Edit Metabase Data dialog box, note that the default value that appears in the Data box is 7697601.
6. To turn off support for the 8bitmime ESMTP verb, type 3503297 in the Data box, and then click OK.
7. To quit the MetaEdit 2.2 utility, on the File menu, click Exit.

The hexadecimal value for 8bitmime is 0x400000H and the corresponding decimal value is 4194304. The hexadecimal values for all verbs that are controlled by the metabase are added together to form a single value that represents the various on or off switches for these verbs. This value in decimal format is stored in the SmtpInboundCommandSupportOptions entry which is equivalent to ID 3699800 in the metabase. The default value for SmtpInboundCommandSupportOptions is 7697601 (0x7574C1H). When you subtract the corresponding decimal value of an ESMTP verb from this number, you can turn on or off the various ESMTP verbs.

To turn off 8bitmime support, subtract the 8bitmime decimal value (41943040) from the default SmtpInboundCommandSupportOptions decimal value (7697601). When you do so, the resulting SmtpInboundCommandSupportOptions value is 3503297 (0x3574C1H).

For additional information about how to turn off ESMTP Verbs , click the following article number to view the article in the Microsoft Knowledge Base: For more information about the IIS metabase, visit the following Microsoft Web site: