The email verification service performs multiple checks on the email.
Hunter validates the format and makes sure it isn’t a temporary address or a webmail. Then, it contacts the mail server (without sending any emails) to make sure there is indeed an email inbox for the requested address.
Here is a more detailed list of verifications that are made for every email processed in the Email Verifier tool:
Valid Format: First, we verify that the format of the email address is correct and looks something like "firstname.lastname@example.org".
Gibberish Email Address: We ensure that the address doesn't look like a random email address. For example, email@example.com doesn't pass the test.
Disposable Email Address: We check if the email address has a domain name used for temporary email addresses.
💡Disposable emails are meant for single uses, e.g. signing up for a service, and can't be used to contact a professional. Due to this, they cannot be verified with Hunter.
Webmail Email Addresses: We verify if the email address uses a webmail like Gmail or Yahoo.
Presence of MX Records: We check if there are Mail Exchange (MX) records on the domain. In simple terms, an MX record points to the SMTP mail server used to receive the emails. If there are no MX records, emails sent to that domain can't be delivered.
Presence of SMTP Server: This check is successful if we are able to connect to the SMTP server (indicated in MX records).
SMTP Check: We test the email address to see if it exists. In case the SMTP server prevents us from performing this verification, we will mark the email as "Blocked".
Accept-All Domain: We check if the server has a catch-all policy that accepts all incoming emails, even if the specified mailbox does not exist. An email address marked as "Accept-All" may still bounce in a minority of cases.