Had to share this as I´m getting tired of companies selling out my email to advertisers, leaked to spammers or them starting to spam my inbox just because I once registered on their service. So by adding a company-specific string to your email-address you can filter all spam and identify the origin of who sold out your address. E.g., I tested this when buying a travel ticket. Upon registration I did not provide them with my original email-address (email@example.com), but rather an address specifically crafted for this travel service agency (firstname.lastname@example.org). I will still receive the emails from the company, but also filter out its origin, even if they shared it with cooperating companies or advertisers.