Honestly don't see a reasonable way to do that. Spammers use a mixture of email address types. Obviously things like mail.ru come up a lot but so do nonsense combinations @gmail.com, outlook.com etc etc but also just a name and some numbers. Theere isn't really a recognisable catch all format.
Registration IPs from the usual places like India, Vietnam, Russia, Ukraine, China to name but a few but if you're not careful you could easily delete a valid account.
Any accounts older than 6 months will never be returned to anyway so you're probably not solving much. Best bet might be to try and order the memberlist by website and delete the ones that look dodgy like anything mentioning pills, diets, dating, removals, medical practices, limos, SEO services, poker, casinos etc.