Some years ago I used the + feature in my gmail address. e.g. myname+ycombinator@gmail.com to track down which service is giving away my email address. It happened more than once that I could not log in anymore at some point because they started to disallow the + character in email addresses. I also got phone calls from some companies complaining that i misspelled my email address because there was their company name in it.
hehe, did the same, although not with +, but using a catch-all feature of the provider. I still get a lot of spam and phishing attempts on my „dropbox@<mydomain>“ address. I faintly remember they (dropbox) had a breach some time in the past.
