If you want a fully functioning mailbox that you can treat as temporary:
Even a disposable alias looks more credible when it ends in @yourname.com rather than @sharklasers.com . create temporary email with custom domain
Offers specialized "disposable addresses" where you can use domains like @secret.fyi or your own. If you want a fully functioning mailbox that
Depending on your technical skill and budget, here are the best ways to set this up: create temporary email with custom domain