I use Cloudflares email routing.
Point my domains name servers to Cloudflares and enable email routing. I can then create any email address in that domain and have it forward to any of my email addresses. Works great when signing up for accounts. The only thing you can't do is fire off email FROM said email address
Edit: can to can't
It only routes / forwards emails to your inbox from that domain. You can put a catch all rule or direct certain emails to different inboxes. You can't send emails from the domain in Cloudflare