A bounce is when an email doesn’t go through to the recipient and is returned to the server. There are two kinds of bounces- a hard bounce and a soft bounce. A hard bounce is when an email is returned because the email address is invalid. A soft bounce is when an email is returned because the server is temporarily unavailable. If you get a lot of bounces, it’s important to remove invalid email addresses from your list so you don’t continue to trying to send emails to them. It can also be helpful to use an email verification service to clean your list before you send your next campaign.