message-send-form-letter-delay

message-send-form-letter-delay is a variable defined in `message.el'.
Its value is

1

Documentation:
Delay in seconds when sending a message with `message-send-form-letter'.
Only used when `message-send-form-letter' is called with non-nil
argument `force'.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 23.1 of Emacs.