Sub AddHeader ( m As Outlook.MailItem , strProjectNumber As String ) 'Dim m As Outlook.MailItem Dim pa As Outlook.PropertyAccessor Dim myOlFormat As Integer myOlFormat = m.BodyFormat m.BodyFormat = olFormatUnspecified 'Set m = Application.CreateItem(olMailItem) 'm.Body = m.Subject Set pa = m.PropertyAccessor pa.SetProperty "http://schemas.microsoft.com/mapi/string/{00020386-0000-0000-C000-000000000046}/X-MS-Exchange-Organization-AECOM-Project" , strProjectNumber Select Case myOlFormat Case olFormatHTML m.HTMLBody = m.HTMLBody & vbCr & " [X-MS-Exchange-Organization-AECOM-Project:" & strProjectNumber & "] " m.HTMLBody = m.HTMLBody & vbCr & " [X-MS-Exchange-Organization-AECOM-Project:" & strProjectNumber & "] " Case olFormatPlain , olFormatRichText , ol