Email certainty

When you fetch your results, we give you information about the email addresses that we found. As we cannot be always certain that an email address exists, we develop a scale that give you our certainty. Below you'll find the different kind of level:

Certainty	Type of search	Meaning
very_sure / ultra_sure	all	99% confidence level: expected bounce rate inferior to 1%.
probable	all	95% confidence level: expected bounce rate inferior to 5%.
undeliverable	email-verification	The email address does not exist.
not_found	domain-search / email-search	We have not found an email address for this domain or this person
not_found	email-verification	We do not know if this email address exists or not