MemoryStream - Cannot access a closed Stream

One simple approach is to get the byte array out of the closed MemoryStream and create another one:

pdf.CreatePDF(ms)
ms = new MemoryStream(ms.ToArray())

Dim email As New EmailService
email.Send(ms)

Note that it's fine to call MemoryStream.ToArray on a closed / disposed instance of MemoryStream. It's even documented:

Note
This method works when the MemoryStream is closed.