The conceptual model provided by a :class:`Message` object is that of an
ordered dictionary of headers with additional methods for accessing both
specialized information from the headers, for accessing the payload, for
-generating a serialized version of the mssage, and for recursively walking over
-the object tree. Note that duplicate headers are supported but special methods
-must be used to access them.
+generating a serialized version of the message, and for recursively walking
+over the object tree. Note that duplicate headers are supported but special
+methods must be used to access them.
The :class:`Message` pseudo-dictionary is indexed by the header names, which
must be ASCII values. The values of the dictionary are strings that are