A hard bounce is logged when there is an attempt to deliver an email message but the delivery is rejected due to a permanent error, such as an invalid email address. The most common cause of email bounces is a typo in the email address.
A soft bounce is logged when an email is sent, processed by the subscriber’s server and then the message is returned. Soft bounces may occur if the server is not available or if the mailbox is over its size limit.
What is the difference between a hard and soft bounce?">← What is the difference between a hard and soft bounce?