[professorsnep]

I've been doing the catch-all signup for over a decade myself and haven't had any issues. What service checks stuff like that?

[judge2020]

I can't find it now, but there was a mildly populae HN thread about a service that does "email validation" and part of it did catch-all detection, and there do seem to be other services that market this[0].

0: https://www.email-validator.net/blog/validating-catch-all-em... (warning: annoying marketing page)