I have addresses like somename-ex-someservice@mydomain.com directed to my email, which I use to register myself in "someservice". This is how I know where email

I have addresses like somename-ex-someservice@mydomain.com directed to my email, which I use to register myself in "someservice". This is how I know where email was leaked and needs to be disabled. I use Protonmail basic subscription to attach my domain. Before that I was using rewriting rules in Postfix.