diff --git a/Lib/mailbox.py b/Lib/mailbox.py
index 8b00460..73fe7d6 100644
--- a/Lib/mailbox.py
+++ b/Lib/mailbox.py
@@ -1443,9 +1443,9 @@
                     line = line[:-1] + b'\n'
                 self._file.write(line.replace(b'\n', linesep))
                 if line == b'\n' or not line:
-                    self._file.write(b'*** EOOH ***' + linesep)
                     if first_pass:
                         first_pass = False
+                        self._file.write(b'*** EOOH ***' + linesep)
                         message.seek(original_pos)
                     else:
                         break