Well try out emailpapaya.com this is free of cost but wait time is very high. if you want immediate charge is $10 per 50K emails
You can use this website to manually see if an email is valid or not: http://www.mailboxvalidator.com/
This one seems to be good tool but is very expensive This one looks like a better option, however it is limited to 1000 email addresses in a single go.
True, but there is API available and with this sample PHP script, you can run any number of email address in a single go with any free hosting.
We have recently released a new platform that can handle up to 1,000,000 emails in one task. So, if you are still in need, feel free to check https://bulk-email-verifier.biz/