mh-identity-default

mh-identity-default is a variable defined in `mh-e.el'.
Its value is

nil

Documentation:
Default identity to use when `mh-letter-mode' is called.
See `mh-identity-list'.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 7.1 of the MH-E package that is part of Emacs 22.1.