Here is my trick...
I have one domain that I can use any email at. For EVERYTHING, I use a different user@ the domain.
When one address starts getting spam, I delete it.
This also lets me know who is giving out emails.
For example, I ordered a ticket from Delta and used the email
[email protected]. About 3 months later, I started getting spam at that address from travel companies. So I knew Delta sold it... I just started bouncing
[email protected].