@item mail-source-directory
@vindex mail-source-directory
-Directory where files (if any) will be stored. The default is
-@file{~/Mail/}. At present, the only thing this is used for is to say
-where the incoming files will be stored if the previous variable is
-@code{nil}.
+Directory where incoming mail source files (if any) will be stored. The
+default is @file{~/Mail/}. At present, the only thing this is used for
+is to say where the incoming files will be stored if the variable
+@code{mail-source-delete-incoming} is @code{nil} or a number.
@item mail-source-incoming-file-prefix
@vindex mail-source-incoming-file-prefix