Just swap the msg out and use the Item directly. Again, I preface this as the Item.SenderEmailAddress isn't blank for me. I'm using office 365.

Dim strGreeting
Dim hrs As Long
Dim mins As Long
Dim lngTime As Long


hrs = Val(Left(Format(Time, "HH:mm"), 2))
mins = Val(Right(Format(Time, "HH:mm"), 2))
lngTime = 60 * hrs + mins


Select Case lngTime
	Case Is <= 720
		strGreeting = "Good Morning"
	Case Is > 960
		strGreeting = "Good Evening"
	Case Else
		strGreeting = "Good Afternoon"
End Select
strGreeting = "Good " & strGreeting


If Item.SenderEmailAddress = "xxxx@yyyyy.co.uk" Then
	Item.BCC = IIf(Len(Item.BCC) = 0, "" ,";") & "ttttttttt@gmail.com"
End If


strBody = Item.HTMLBody
strBody = Replace(strBody, "Good day", strGreeting)
Item.HTMLBody = strBody