This step-by-step article describes how to use an SMTP
transport event sink to add a disclaimer to outgoing SMTP e-mail
Create the event sink
- Create a new Microsoft Visual Basic ActiveX DLL. Name the
project SMTPEventSink, and then name the module Disclaimer.
- Under Project References, add Microsoft CDO for Exchange 2000 Library, and then add Server Extension Objects COM Library.
- Put the following code in the module:
Dim TextDisclaimer As String
Dim HTMLDisclaimer As String
Private Sub IEventIsCacheable_IsCacheable()
'Just returns S_OK.
Private Sub Class_Initialize()
'TODO: Replace the sample disclaimer text with your own text.
TextDisclaimer = vbCrLf & "DISCLAIMER:" & vbCrLf & "Sample Disclaimer Text."
HTMLDisclaimer = "<p></p><p>DISCLAIMER:<br>Sample Disclaimer Text"
Private Sub ISMTPOnArrival_OnArrival(ByVal Msg As CDO.IMessage, EventStatus As CDO.CdoEventStatus)
If Msg.HTMLBody <> "" Then
Dim szPartI As String
Dim szPartII As String
Dim pos As Integer
'Search for the "</body>" tag and insert the disclaimer before that tag.
pos = InStr(1, Msg.HTMLBody, "</body>", vbTextCompare)
szPartI = Left(Msg.HTMLBody, pos - 1)
szPartII = Right(Msg.HTMLBody, Len(Msg.HTMLBody) - (pos - 1))
Msg.HTMLBody = szPartI + HTMLDisclaimer + szPartII
If Msg.TextBody <> "" Then
Msg.TextBody = Msg.TextBody & vbCrLf & TextDisclaimer & vbCrLf
'Commit the content changes to the transport ADO Stream object.
EventStatus = cdoRunNextSink
- Replace the sample disclaimer text with your own disclaimer text, and then
build the DLL.
Register the event sink
To register the event sink, use the Smtpreg.vbs file that
is installed with the Exchange software development kit (SDK).
- At a command prompt, locate the
\Exchange SDK\SDK\Support\CDO\Scripts folder, and then type the following: cscript smtpreg.vbs /add 1 OnArrival SMTPDisclaimer SMTPEventSink.Disclaimer "mail firstname.lastname@example.org"
If this command succeeds, you receive a success
message that is generated by the script.
- To unregister this event,
type the following: cscript smtpreg.vbs /remove 1 OnArrival SMTPDisclaimer
For additional information about managing event bindings, visit the following Microsoft Developer Network (MSDN) Web
Test the event sink
To test the event sink, send an e-mail message to an SMTP recipient
who is external to your organization. The recipient receives a modified
message with the disclaimer text added to the end of the message. Note
If you use a MAPI client, such as Microsoft Outlook, to send the
e-mail message, the recipient does not receive a modified e-mail message. This is because
the e-mail message that is submitted by using MAPI is not in an SMTP format when the e-mail message triggers
the SMTP transport event. Therefore, changes that are made by the code of the event are not persisted.
For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
Cannot change MAPI message contents in a CDO SMTP event sink