Verimail is a bulk verification tool and REST API that verifies email addresses. For every email address you provide we will perform multiple checks and tell you if it is safe to send emails to this address or not. Sending emails to unreachable mailboxes will hurt your delivery rate. If over 10% of your emails are undeliverable, then less than 44% are delivered. It is best practice to clean-up your mailing-list at least once a year.