Another danger can be the fact that some sites may not recognize a particular domain as a valid email, i know that this happens with "10 minutes mails" kind of

Another danger can be the fact that some sites may not recognize a particular domain as a valid email, i know that this happens with "10 minutes mails" kind of services but not sure if it can happens with strange .qq .mf2 .hrbw domains (because let's be honest, if i buy a domain for my email it has to be cheap)