When an email cannot be successfully delivered to an email address, it's called a bounce. This means your email never reached an intended recipient.
There are several reasons why an email might bounce:
- The recipient’s server rejects an email due to a seemingly temporary condition such as a full inbox, a connection cannot be established, or the email is too large.
- The contact’s email address is invalid or does not exist. For example, the email address could be misspelled, deleted, no longer active or fake.
- Your email address has been blocked by the recipient. Your contact may no longer want to receive communications from you.
- Aggressive spam filters or email firewalls. Some companies employ very stringent filters, which treat certain emails as spam based on a variety of factors. To ensure your emails are not flagged as spam you should: make sure you have express permission to email your contacts; make sure your subject line is not misleading; use a clear sender address; use clean clear copy in your emails and provide contacts with valuable content; clean your email lists of any email addresses that have not engaged with your campaigns in a while; and ask contacts to whitelist your email address.
- The recipient has activated an auto-responder or vacation reply. This type of bounce is less worrisome because it means the email did reach the contact’s inbox but they had an autoresponder set up to reply to any emails.