diff -r 8915ff3ac7fa Lib/smtpd.py
--- a/Lib/smtpd.py	Wed Aug 06 23:53:11 2014 +0200
+++ b/Lib/smtpd.py	Wed Aug 06 23:55:44 2014 +0200
@@ -741,33 +741,46 @@
 
 
 class PureProxy(SMTPServer):
-    def __init__(self, *args, **kwargs):
-        if 'enable_SMTPUTF8' in kwargs and kwargs['enable_SMTPUTF8']:
-            raise ValueError("PureProxy does not support SMTPUTF8.")
-        super(PureProxy, self).__init__(*args, **kwargs)
+    def process_message(self, peer, mailfrom, rcpttos, data):
+        data = self._insert_x_peer_header(peer, data)
+        refused = self._deliver(mailfrom, rcpttos, data)
+        # TBD: what to do with refused addresses?
+        print('we got some refusals:', refused, file=DEBUGSTREAM)
 
-    def process_message(self, peer, mailfrom, rcpttos, data):
-        lines = data.split('\n')
+    def process_smtputf8_message(self, peer, mailfrom, rcpttos, data):
+        data = self._insert_x_peer_header(peer, data)
+        refused = self._deliver(
+            mailfrom,
+            rcpttos,
+            data,
+            mail_options=['BODY=8BITMIME', 'SMTPUTF8']
+        )
+        print('we got some refusals:', refused, file=DEBUGSTREAM)
+
+    def _insert_x_peer_header(self, peer, data):
+        x_peer_header = 'X-Peer: %s' % peer[0]
+        newline = NEWLINE
+        if isinstance(data, bytes):
+            x_peer_header = x_peer_header.encode()
+            newline = NEWLINE.encode()
+        lines = data.split(newline)
         # Look for the last header
         i = 0
         for line in lines:
             if not line:
                 break
             i += 1
-        lines.insert(i, 'X-Peer: %s' % peer[0])
-        data = NEWLINE.join(lines)
-        refused = self._deliver(mailfrom, rcpttos, data)
-        # TBD: what to do with refused addresses?
-        print('we got some refusals:', refused, file=DEBUGSTREAM)
+        lines.insert(i, x_peer_header)
+        return newline.join(lines)
 
-    def _deliver(self, mailfrom, rcpttos, data):
+    def _deliver(self, mailfrom, rcpttos, data, mail_options=[]):
         import smtplib
         refused = {}
         try:
             s = smtplib.SMTP()
             s.connect(self._remoteaddr[0], self._remoteaddr[1])
             try:
-                refused = s.sendmail(mailfrom, rcpttos, data)
+                refused = s.sendmail(mailfrom, rcpttos, data, mail_options)
             finally:
                 s.quit()
         except smtplib.SMTPRecipientsRefused as e: