mh-alias-expand-aliases-flag

mh-alias-expand-aliases-flag is a variable defined in `mh-e.el'.
Its value is

nil

Documentation:
*Non-nil means to expand aliases entered in the minibuffer.

In other words, aliases entered in the minibuffer will be
expanded to the full address in the message draft. By default,
this expansion is not performed.

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.