I am receiving a lot of bounce-back emails, what does this mean?

1. Bounce-back emails could have several reasons. Check if the email address you are sending to is correct.
2. Check if the email server you are sending from is blocked by the email server you are sending to.
3. If you are using an email provider like Outlook or Gmail, make sure Barracuda or similar security settings is not blocking the emails you are sending.
4. Make sure you have enough balance in your account and if not, request a top-up.