How to delete a phrase from email? - vba

Question

I'd like to remove the following phrase from the beginning of every email from sources other than a specific domain:
"This is an EXTERNAL email. Do not click links or open attachments unless you validate the sender and know the content is safe."
I am trying to delete this phrase from each email.
I grabbed some code online from another person trying to do something similar.
Sub Del()
Dim Ins As Outlook.Inspector
Dim Document As Word.Document
Dim Word As Word.Application
Dim Selection As Word.Selection
Set Ins = Application.ActiveInspector
Set Document = Ins.WordEditor
Set Word = Document.Application
Set Selection = Word.Selection
Dim search As String
search = "This is an EXTERNAL email. Do not click links or open attachments unless you validate the sender and know the content is safe."
Dim para As Paragraph
For Each para In Document.Paragraphs
Dim txt As String
txt = para.Range.Text
If InStr(txt, search) Then
para.Range.Delete
End If
Next
End Sub
I get
Run-time error '91'
on line 9 Set Document.

Answer 1

that works a lot easier within Outlook:
sub delete_part_of_text()
Dim search As String
search = "This is an EXTERNAL email. Do not click links or open attachments unless you validate the sender and know the content is safe."
If Not TypeOf Item Is mailitem Then Exit Sub
Item.HTMLBody = Replace(Item.HTMLBody, search, "")
end sub
of course you have to adapt this - should this run automatically on each incoming mail oder are you going to call this when needed for one/some mails? That changes the call of the procedure, but the princip abobe works.
Max