How to Load Exchange SMTP Properly

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For mail to flow properly, SMTP must be installed correctly on the Exchange server with all of the necessary commands. If you experience mail problems, you should first verify the basic functionality of your SMTP installation.

When an Exchange server uses SMTP to communicate, it must have access to port 25. When SMTP is configured correctly, Exchange provides extended SMTP verbs to allow for proper communication. These verbs are controlled in the Internet Information Services (IIS) metabase and in Exchange event sinks.

Before You Begin

Before you perform the procedure in this topic, read Connecting Exchange to the Internet.

The following permissions are required to perform this procedure:

  • Member of the local administrators group

To determine whether or not the proper extended Exchange verbs are loaded, you can perform a telnet test. To perform this test, telnet to port 25 of your Exchange server's IP address. For example, type the following text at a command prompt:

telnet <server IP address> 25

where server IP address is the IP address of your Exchange server, and 25 indicates a connection to TCP port 25. The following example shows a telnet command to connect to port 25 on a server with an IP address of 172.16.0.1:

telnet 172.16.0.1 25

Next, type ehlo <server name>,where server name is the fully qualified domain name (FQDN) of your Exchange server. Your Exchange server then responds by listing the SMTP and ESMTP verbs that it supports.

Procedure

To load Exchange SMTP properly

  1. Uninstall IIS.

  2. Delete the metabase.bin file.

  3. Restart the server.

  4. Reinstall IIS.

  5. If you are running Exchange Server on a Windows 2000 server, reapply the latest Windows 2000 service pack.

  6. Reinstall Exchange Server. Reinstalling Exchange Server replaces any missing files and does not affect the settings on the Exchange server.

  7. Reapply any Exchange Server service packs and any other Exchange-related program updates (for example, any Exchange updates that are available from the Microsoft Web site).

    Note

    Subscribe to the Microsoft Security Notification Service to receive notifications automatically about any security-related Exchange updates. You can register for the service at https://go.microsoft.com/fwlink/?LinkId=12322.

Example

Example 1 lists the verbs that you will receive if SMTP is loaded properly. If SMTP is not configured properly, you will see only the verbs that are listed in Example 2.

Example 1:   SMTP extended verbs (if Exchange event sinks are loaded properly)

         
250-mail1.example.com Hello [172.16.0.1]
250-TURN
250-ATRN
250-SIZE 5242880
250-ETRN
250-PIPELINING
250-DSN
250-ENHANCEDSTATUSCODES
250-8bitmime
250-BINARYMIME
250-CHUNKING
250-VRFY
250-X-EXPS GSSAPI NTLM   *
250-AUTH GSSAPI NTLM
240-X-EXPS=LOGIN  *
250-X-LINK2STATE  *
250-XEXCH50   *
250 OK

*  These extended verbs should be displayed.

When Exchange SMTP is not loaded properly, or the IIS metabase is corrupt, the extended Exchange verbs do not appear in the server's response. Example 2 lists the verbs that you will receive if Exchange SMTP is not loaded properly.

Note

The verbs that are listed in Example2 are the same as the verbs you would see if you had never installed Exchange.

Example 2:   SMTP extended verbs (if Exchange 2003 event sinks are not loaded)

         
250-mail1.example.com Hello [172.16.0.1]
250-TURN
250-ATRN
250-SIZE 5242880
250-ETRN
250-PIPELINING
250-DSN
250-ENHANCEDSTATUSCODES
250-8bitmime
250-BINARYMIME
250-CHUNKING
250-VRFY
250-AUTH GSSAPI NTLM
250 OK

If you receive only the SMTP verbs that are listed in Example 2, the SMTP service for Microsoft Windows® 2000 Server or Windows Server 2003™ is installed, but SMTP in Exchange is not loaded properly. Note that all verbs starting with "X" ("X" = eXtended) are missing.

Other incomplete lists can also indicate that Exchange Server is not properly loaded, or that there is a possible corruption of the IIS metabase. Corruption of the IIS metabase can occur for any of the following reasons:

  • Reinstalling Exchange Server 2003

  • Reinstalling Windows 2000 Server or Windows Server 2003

  • Removing or disabling IIS

  • Antivirus software scanning the %systemroot%\system32\inetsrv\metabase.bin file

  • IIsadmin.exe process stopped unexpectedly (ungraceful shutdowns)

  • Unsupported editing of the metabase

  • Disk corruption or other hardware failures

If there is corruption to the IIS metabase, you must load Exchange SMTP properly.

Note

If you perform this procedure, any customizations to the IIS services will be lost. This potential loss includes customization that is performed on Microsoft Office Outlook® Web Access or any other IIS services.