There are two types of bounces, hard and soft.
A hard bounce happens when an email is sent to an invalid email address
A soft bounce occurs when an email is sent to an inbox that temporarily cannot receive emails because of things like maintenance or being full.
Why Does This Matter?
The ESPs out there like Gmail and Yahoo monitor your every sending move; they want to make sure that you’re only sending mail to people who have recently indicated they want to hear from you. Mailing a list that draws a lot of bounces generally indicates that it’s old, meaning that it either hasn’t been mailed in a long time or hasn’t been cleaned of bad email addresses in the past. Whatever the culprit, the outcome is the same. The ESPs see the poor mailing rates and then start to send more and more of your mail (and our other customers who share your IP) to the spam box or even block it outright.
This is why our bounce threshold of 7% protects us and you, conforms to industry standards to keep us off ISP blacklists and ensures that no one can singlehandedly destroy the collective mailing reputation. It’s how we keep delivery issues manageable and delivery rates soaring.
How can I avoid a high bounce rate in the future?
A. Ensure that only explicit, recent opt-ins are mailed through your account. Someone handing you a business card in passing at a trade show is not considered permission. If you’re worried about your previous service not unsubscribing your hard bounces run your list through a service like Briteverify before importing into ONTRAPORT.
This didn't happen at my last email service. Why here?
A. It's possible that your previous service had more lax policies than those at ONTRAPORT. When services have a high tolerance for spammy behavior, it’s your delivery that suffers. We consider email delivery extremely important and are committed to serving clients who are willing to abide by the highest standards.