try like

Code:
For Each subdoc In doc.Subdocuments
Set newdoc = subdoc.Open
'Remove NextPage section breaks
'originating from mailmerge
RemoveAllSectionBreaks newdoc
With newdoc
addr = .tables(1).Cell(13, 2).Range.Text
addr = left(addr, len(addr) - 1)
.SaveAs FileName:="MergeResult" & addr & ".doc"
.Close
End With
docCounter = docCounter + 1
Next subdoc
note the @ character may not be valid in filenames and may need to be replaced