When an email is rejected by a subscriber's email server, it's called a bounce. There are two different types of bounces, soft and hard and they depend on the reason the email bounced.


Hard bounces:

  • an e-mail address that does not exist
  • a domain that does exist 
  • e-mail server that has completely blocked delivery


Soft bounces:

  • the e-mail box was full
  • the server was down 
  • the message was too large.