Dim myMimeMultipartRelatedBinding As MimeMultipartRelatedBinding = Nothing
Dim myIEnumerator As IEnumerator = myOutputBinding.Extensions.GetEnumerator()
While myIEnumerator.MoveNext()
   myMimeMultipartRelatedBinding = CType(myIEnumerator.Current, MimeMultipartRelatedBinding)
End While
' Create an instance of 'MimePartCollection'.
Dim myMimePartCollection As New MimePartCollection()
myMimePartCollection = myMimeMultipartRelatedBinding.Parts
Console.WriteLine("Total number of mimepart elements in the collection initially" + _
                                             " is: " + myMimePartCollection.Count.ToString())
' Get the type of first 'Item' in collection.
Console.WriteLine("The first object in collection is of type: " + _
                                                      myMimePartCollection.Item(0).ToString())
Dim myMimePart1 As New MimePart()
' Create an instance of 'MimeXmlBinding'.
Dim myMimeXmlBinding1 As New MimeXmlBinding()
myMimeXmlBinding1.Part = "body"
myMimePart1.Extensions.Add(myMimeXmlBinding1)
'  a mimepart at first position.
myMimePartCollection.Insert(0, myMimePart1)
Console.WriteLine("Inserting a mimepart object...")
' Check whether 'Insert' was successful or not.
If myMimePartCollection.Contains(myMimePart1) Then
   ' Display the index of inserted 'MimePart'.
   Console.WriteLine("'MimePart' is succesfully inserted at position: " + _
                                      myMimePartCollection.IndexOf(myMimePart1).ToString())
End If