See note in comments in the code below.
This is one way: 
Sub blah2()
mypath = "W:\.Team Documents\Freehold Team\Mainstay\Reporting\Reports"    'note no final backslash. Not needed if you use the next line.
myfile = mypath & "\Mainstay Master.xlsx"    'note leading backslash

'if you use the line below (currently commented out) you can delete the 2 lines above.
'myfile = ThisWorkbook.Path & "\Mainstay Master.xlsx"    'use this to save the new file in the same folder as this workbook

sto = Join(WorksheetFunction.Transpose(ThisWorkbook.Sheets("Control").Range("Final")), ";")
Sheets(Array("Mainstay Master", "Mainstay Report")).Copy
Set NewBk = ActiveWorkbook
NewBk.SaveAs myfile
Set ol = CreateObject("Outlook.Application")
Set msg = ol.Createitem(0)
With msg
  .To = sto
  '.cc = scc 'don't know where this scc comes from
  .Subject = "Mainstay Report & Master file"
  .Body = "Good Morning"
  .attachments.Add myfile
  .display
End With
NewBk.Close    'if you want
End Sub