diff --git a/Doc/library/smtpd.rst b/Doc/library/smtpd.rst
--- a/Doc/library/smtpd.rst
+++ b/Doc/library/smtpd.rst
@@ -2,7 +2,7 @@
 ============================
 
 .. module:: smtpd
-   :synopsis: A SMTP server implementation in Python.
+   :synopsis: An SMTP server implementation in Python.
 
 .. moduleauthor:: Barry Warsaw <barry@python.org>
 .. sectionauthor:: Moshe Zadka <moshez@moshez.org>
@@ -49,7 +49,8 @@
       attribute. *peer* is the remote host's address, *mailfrom* is the envelope
       originator, *rcpttos* are the envelope recipients and *data* is a string
       containing the contents of the e-mail (which should be in :rfc:`2822`
-      format).
+      format). *mailfrom*, *rcpttos* and *data* have been decoded as
+      latin1.
 
    .. attribute:: channel_class
 
@@ -130,7 +131,7 @@
 
    .. attribute:: received_lines
 
-      Holds a list of the line strings (decoded using UTF-8) received from
+      Holds a list of the line strings (decoded using latin1) received from
       the client. The lines have their ``"\r\n"`` line ending translated to
       ``"\n"``.
 
diff --git a/Lib/smtpd.py b/Lib/smtpd.py
--- a/Lib/smtpd.py
+++ b/Lib/smtpd.py
@@ -287,7 +287,7 @@
             return
         elif limit:
             self.num_bytes += len(data)
-        self.received_lines.append(str(data, "utf-8"))
+        self.received_lines.append(str(data, "latin1"))
 
     # Implementation of base class abstract method
     def found_terminator(self):