\begin{methoddesc}[mailbox]{next}{}
Return the next message in the mailbox, created with the optional
\var{factory} argument passed into the mailbox object's constructor.
-By defaul this is an \class{rfc822.Message}
+By default this is an \class{rfc822.Message}
object (see the \refmodule{rfc822} module). Depending on the mailbox
implementation the \var{fp} attribute of this object may be a true
file object or a class instance simulating a file object, taking care