I also use some email providers ability to have +xyz at the end of the username. So for a registration I would for user.name+sitea@domain.com. has helped me track spam and leaks in the past.
It works 95% of the time, but be aware that it sometimes doesn't:
- Some webpages refuse addresses with a + in it.
- I’ve had at least one instance where I lost an important email because I could register and receive emails from them, but one of their internal databases silently failed on my address. (I lost the proofs for a paper accepted in a journal, and it took some time to figure out what was going on…)
- There was at least one web page that was smart enough to just remove the +… from my address after I registered.
- Some webpages require you to be able to send emails to them from the exact address you sign up with (including the +…)
Overall I’ve been happy with the feature since it makes e-mail sorting easier, and you can just redirect a given subaddress to spam if they leak it, and it’s less effort than creating a “real” email alias per page. Just keep in mind that there are many ways it can fail, so you might not want to use it for anything that is actually important.
Name@email.com is n.ame@email.com is n.a.me@email.com is n.am.e@email.com etc
e.g andrew@gmail.com, a.n.d.r.e.w@gmail.com and a.....ndrew@gmail.com all are the same user and will go into their mailbox (which I have used to avoid the + stripping that some sites do)
andrew@outlook.com and a.ndrew@outlook.com are two distinct users.
Obviously if you control the domain or use a provider who supports it you can add an alias with punctuation but then you might as well just use e.g ebay@c.com to track the email source.
I do have a “real” email alias as well that I use for true spam (e.g. to get “customer club” discounts while everything they send me is autoredirected to spam by a mail filter). I reserve the + addresses for things I want in my inbox, but still want to be able to filter easily in my mail client.