Emailing User Defined Ranges

Hi Guys, I hope you are all well today

I was wondering if anyone could help me with the below. I am trying to use the below code to email user defined ranges(the name of the range is shown as a value in first cell, the emaill address is in the 2nd with information below). on sheet 2 of a workbook. but every time I run the macro it errors with :

Compile Error:

Loop Without Do.

 
    Sub Email_Ranges()
    Dim rG As Range
    Dim RangeToSend As Range
    Dim CustomerMail As String

    Set rG = ActiveWorkbook.ActiveSheet.[b1]

    ActiveWorkbook.EnvelopeVisible = True

    Do While rG.Value <> vbNullString
        CustomerMail = rG.Value
        Set RangeToSend = rG.Offset(, -1).Resize(30, 2)

        With RangeToSend.Parent.MailEnvelope

        ''Uncomment below if you get an error
        rG.Parent.Activate
        RangeToSend.Select
        With Selection.Parent.MailEnvelope

            .Introduction = "Good Morning"
            With .Item
                .To = CustomerMail
                .Subject = "Just testing, sorry for filling your inbox ^_^ "
                .display    'to test
                .Send      'to send
            End With
        End With
        Debug.Print CustomerMail & " receives " & RangeToSend.Address
        Set rG = rG.Offset(, 2)
    Loop

    ActiveWorkbook.EnvelopeVisible = False
End Sub

any help would be greatly appreciated

Many thanks

jamie