How can I get the sender email address using Outlook.MailItem in VB.NET?

Question

I have tried using mailItem.SenderEmailAddress and mailItem.Sender.Address but they both return a string that looks like this:

/O=DO

Answer 1

Created a VBA function if you wanted to use it for simplicity. A sample call would be Left(GetEmailAddress(mai) & Space(50), 50) where mai is expected to be a MailItem object. Used and tested successfully in Microsoft Outlook 2010

Public Function GetEmailAddress(mai As Object) As String
    On Error Resume Next
    Set ObjSelectedItem = mai
    If TypeName(ObjSelectedItem) = "MailItem" Then
        If ObjSelectedItem.SenderEmailType = "EX" Then
            GetEmailAddress = ObjSelectedItem.Sender.GetExchangeUser.PrimarySmtpAddress
        Else
            GetEmailAddress = ObjSelectedItem.SenderEmailAddress
        End If
    Else
        GetEmailAddress = "Not a MailItem"
    End If

    Set ObjSelectedItem = Nothing
    End Function