Here is a workable idea, if I could just convince Gmail to try it.
When you sign up for an email address you can have the option of using
a permission only email address. You always have the option of using
your regular email address email@example.com that passes everything,
but Gmail also gives you an address like firstname.lastname@example.org
Anything going to email@example.com (spamblock) would be blocked.
The contacts you have for firstname.lastname@example.org are automatically passed
to the permission only address. Any email you send from either
address will be white listed and passed to the permission only
You can also have Gmail store passwords so that any emails that have
the password in the subject and/or body will pass. You can use more
than one password that can be permanent or expire.
Hint. Your first name or nickname would be a good permanent password
that you could give to your friends and put on business cards.
You could even post your permission only address on Usenet with a
password that expired every month.
email@example.com put crazyhead in the subject for permission to