Email Addresses

https://hunter.io/ - Hunter - performs fast scan of the domain name for email addresses and reveals its common pattern.
http://metricsparrow.com/toolkit/email-permutator/# - Email permutator - generates permutations of up to three domains at which target is likely to have an email address. Supports multiple variables input to generate custom results.
https://proofy.io/ - Proofy - allows bulk email validation which is useful when you generated a list of emails using a permutation tool and want to check all of them at once.
https://verifalia.com/validate-email - Verifalia - validates single email addresses for free without registration. To use bulk validation you have to sign up.