I just sent out a rejection regarding a really neat idea that wasn’t right for me. And I received a nice form letter in response, to whit:
I apologize for this automatic reply to your email.
To control spam, I now allow incoming messages only from senders I have approved beforehand.
If you would like to be added to my list of approved senders, please fill out the short request form (see link below). Once I approve you, I will receive your original message in my inbox. You do not need to resend your message. I apologize for this one-time inconvenience.
No, that’s okay, really, but thanks for the query!
Seriously, do you really want potential agents and publishers to jump through hoops to contact you?