message-allow-no-recipients

message-allow-no-recipients is a variable defined in `message.el'.
Its value is

ask

Documentation:
Specifies what to do when there are no recipients other than Gcc/Fcc.
If it is the symbol `always', the posting is allowed. If it is the
symbol `never', the posting is not allowed. If it is the symbol
`ask', you are prompted.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 22.1 of Emacs.