As I run my own mail server, what I do is always creating an alias, usually named after the website I subscribe. Like expedia@mydomain.com for example.

This way I can stop unwanted mail if unsubscribe does'nt work by deleting the alias.

It also help to see who is selling your email.

For example, some years ago, I had the problem with bitdefender, as I subscribed as a reseller (!). I explained what I thought about it to my sell representative, who couldn't find a decent explanation. And stop selling their product. And destroy the alias.

Why not spamdecoy.net? It does the same thing and you never give your real email to anyone (though forward cat is open source so it's probably ok), and you don't have to set up anything before you use the temporary email.

tempmail.de (http://tempmail.de/) do not ask you for your real email adress