[jmkni]

I have my own domain and a catch-all setup, so when I sign up for a service, it's [e-mail], if I give someone my email address, it's [e-mail]

It makes it easy for me to keep track of who is sending me what + who is sharing my email with third parties, but definitely confuses some people.

[jeroenhd]

Samsung is particularly annoying about this. You can't sign up for an account with "Samsung" in the user portion. They'll straight up block [e-mail], so I've resorted to misspelling their name in the email address and they seem perfectly fine with that.

[sidharthv]

I've been using sam.sung@domain for them. First time I've come across this block in years of using this method.