Autoresponder conditional

Hi,

Is it possible to have a condition for the autoresponder –Mail2? Email address is not a required field in my form, so I’d like to configure the autoresponder to:
— if an email address is entered in the form, then the autoresponder goes to that email (this works well)
— if no email is entered in the form, I’d like the autoresponder to go to a default address I determine. This is what I don’t know how to set up.

Has anyone done something like this?