When setting up accounts or handing out my email address, I use a catchall on a different domain I have, giving a different mailbox to each sender. So, for instance if I give my address to Bob’s Cream Puffs to get a coupon, it might be email@example.com. You can do this with a normal (non-catch-all) address too, by using the plus sign after the mailbox name. In my case, that would be something like firstname.lastname@example.org. That trick even works with GMail and a number of other web services.