Microsoft CRM customization: MS Exchange Transport SMTP Event Sink in VB.NET

Microsoft CRM has variety of customizations options and tools. The official and the most popular is Microsoft CRM SDK: collection of C#.Net and partially VB.Net classes, methods and code samples. Here we would like to give you more complex case, when you call CRM SDK customization from custom MS Exchange event handler - we are improving the functionality of MS Exchange - MS CRM connector.

Imagine the case when you want outgoing email to be captured and placed into CRM, attached to Contact, Account or Lead they should belong to. If this is realized - your salespeople can use any email tool to send their messages, they do not have to do it in CRM or Outlook Client for CRM.

MS Exchange OnSyncSave database event can't work with Sent folder - it doesn't fire when message goes to Sent folder. The reason is described here:

PRB: Store Events Do Not Fire on the Outbox or Sent Item Folders
http://support.microsoft.com/default.aspx?scid=kb;en-us;Q297274

Please, see SMTP Event Sink example in this article:
 http://support.microsoft.com/default.aspx?scid=kb;en-us;317327.

Event handler works OnArrival event:

Private Sub OnArrival(ByVal msg As CDO.IMessage, ByRef EventStatus As CDO.CdoEventStatus) Implements ISMTPOnArrival.OnArrival
log = LogManager.GetLogger(GetType(ShieldsUp))
DOMConfigurator.Configure(New FileInfo(Environment.SystemDirectory & "/CustomerApp/log.config"))
Try
ProcessMessage(msg)
Catch ex As Exception
log.Debug(ex.Message + Constants.vbLf + ex.StackTrace)
Finally
LogManager.Shutdown()
End Try
End Sub

The class:

' ComVisible enables COM visibility of this class. The default is true.
' Explicitly setting this attribute to true, as shown below, is useful
' if ComVisible is set to false for the namespace and you want the
' classes to be accessible individually.

<ComVisible(True)> _
Public Class ShieldsUp : Inherits CDO.ISMTPOnArrival
Next the handling works similar to SyncSave handler:
Private Sub ProcessMessage(ByVal msg As CDO.IMessage)
Dim sFrom As String
Dim sTo As String
Dim sSubject As String
Dim sBody As String
Dim sSensitivity As String
Try
log.Debug("Firing Up ProcessMessage()")
sSubject = msg.Subject
sBody = msg.TextBody
sFrom = msg.From
sTo = msg.To
If Not msg.Fields("urn:schemas:mailheader:sensitivity").Value Is Nothing Then
sSensitivity = msg.Fields("urn:schemas:mailheader:sensitivity").Value.ToString()
Else
sSensitivity = "Normal"
End If
log.Debug("Message From: " & sFrom)
log.Debug("Message To: " & sTo)
log.Debug("Subject: " & sSubject)
log.Debug("Sensitivity: " & sSensitivity)
log.Debug("Body: " & sBody)

In deployment you should consider the following - the handler will work only in the case of SMTP protocol delivery. If you use Outlook or Outlook Web Access, then delivery uses MAPI and OnArrival doesn't fire. Please see this article:
 http://support.microsoft.com/default.aspx?scid=kb;en-us;273233 The elegant fix is two SMTP gateways, find it here http://support.microsoft.com/default.aspx?scid=kb;en-us;Q288756 

NOTE: THIS ARTICLE IS CONVERTED FROM C# TO VB.NET USING A CONVERSION TOOL. ORIGINAL ARTICLE CAN BE FOUND ON C# CORNER (WWW.C-SHARPCORNER.COM).