Within any organization, an Exchange administrator may wish to have a header or footer attached to all incoming
or outgoing messages, such as a disclaimer or other legal notice. Doing this requires use of the Internet Mail Service Extension DLL, known as IMSEXT.DLL.
This .DLL is included with the Microsoft BackOffice Resource Kit and is not installed by default, so it needs to be installed before it can be used.
- Copy the IMSEXT.DLL file to the ExchsrvrConnectMsexcimcBin folder on the Exchange server in question.
- In that folder, run the command
This will register the DLL with Windows.
- If you are running Exchange Server 5.5 SP1 or later, you'll need to make a Registry edit to avoid losing routing tables. Under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchange\IMCParameters, add the following value:
Value Name: NonRoutingExtensionDll
Data Type: REG_SZ
String Value: Drive and path to IMSEXT.DLL
- Under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchange\IMCParameters, add a new key named Extension.
- Stop and restart the Internet Mail Service.
- In the Extension key, add the following values based on what kind of messages you want to add to incoming or outgoing mails.
To have incoming mail sport a header text in the body of the message, add a string value named InboundPrepend. For appended text, add a string value named InboundAppend.
To add a header to outbound messages, add a string named OutboundPrepend. To append text, add a string named OutboundAppend.
The value of each of these strings is the text of the message to add, with the following RTF-style control characters:
\b -- Bold on
\b0 -- Bold off
\i -- Italics on
\i0 -- Italics off
\ul -- Underline on
\ul0 -- Underline off
\plain -- Plaintext--All formatting off
\par -- New line or new paragraph
\tab -- Tab in five spaces
So to encode the message
This mail has been sent in confidence.
If you are not the recipient, contact email@example.com immediately.
-- use the following text:
This mail has been sent in confidence.par If you are not the recipient, contact firstname.lastname@example.org immediately.
Note the use of par for the line break.
Serdar Yegulalp is the editor of the Windows 2000 Power Users Newsletter.