How to check a list of emails for real / fake addresses?

Hello guys,

What’s the best way to check thousands of emails to make sure they are legit and real? Is there anything we can use that doesn’t have some kind of credits system? My client sent me a huge list of emails to send for outreach, but after 2 days, a lot of the emails bounced. Any way we can clean it up without forking over a big wad of cash?

Thank you.

Not sure about how to check if an email is legit or not. The only way I can think of as well is to send them emails and see which ones return with a mailer daemon but that’s tedious. Hoping we get answers from the rest of the guys here.