Creating New Message with default signature using Exchange Web Services

Question

Currently a piece of our application creates and saves new mail messages to a user's drafts folder using Exchange Web Services. We would like to automatically append the user's default signature to these messages when creating them, but I have not been able to find a way to access the signature to append it to the body. The email message is currently created with the following code:

CreateItemType createEmailRequest = new CreateItemType();
createEmailRequest.MessageDisposition = MessageDispositionType.SaveOnly;
createEmailRequest.MessageDispositionSpecified = true;

DistinguishedFolderIdType draftsFolder = new DistinguishedFolderIdType();
draftsFolder.Id = distinguishedFolderIdNameType;
createEmailRequest.SavedItemFolderId = new TargetFolderIdType();
createEmailRequest.SavedItemFolderId.Item = draftsFolder;

MessageType emailMessage = new MessageType();
emailMessage.Subject = subject;
emailMessage.Body = new BodyType();
emailMessage.Body.BodyType1 = bodyType;
emailMessage.Body.Value = body;
emailMessage.Sensitivity = SensitivityChoicesType.Normal;
emailMessage.SensitivitySpecified = true;

createEmailRequest.Items = new NonEmptyArrayOfAllItemsType();
createEmailRequest.Items.Items = new ItemType[1];
createEmailRequest.Items.Items[0] = emailMessage;

Any ideas on how to get the current user's default signature and append it to the body the email?