Both Gmail and Fastmail supports "+something" in the local part of your email address, so you can just add a foo+*@domain filter to block everything or move it to a folder, and then add a foo+someapprovedsender@domain filter before it for anyone you want to reach your inbox.
Almost every provider (social media, banks, websites and spammers) also know this, and routinely remove anything after + in @gmail addresses.
Indian Retirement Fund website, NPS, government operated, will take your abc+nps@gmail.com at signup, no errors, but will not let you login saying, Email Not Found. You have to login with abc@gmail.com to get in your account.
All the places I've given addresses like that dutifully e-mails to the right place, so I guess I must've gotten lucky. But if you use your own domain with Fastmail (which I'd recommend anyway, so you have an easy way of moving elsewhere if you need to - how I was able to migrate to Fastmail from Google relatively painlessly in the first place) you can also set up catchall addresses so you can use the whole local-part instead:
Fastmail supports both yourname+foo@example.com and foo@yourname.example.com. I use the latter precisely to avoid the problem of sites that don't play well with plus addresses.
