Usually when this happens, it means the email address is either invalid or the recipient blocked all emails from that sender. When a hard bounce occurs, some email service providers automatically remove that recipient from their mailing list so it doesn’t happen again in the next campaign.
Too many hard bounces can be a red flag for spam filters. In order to make sure your messages don’t get marked as spam, you need to constantly maintain your email list.
You can do that by:
- Avoiding bought email lists
- Making sure your emails are relevant
- Not using free sender domains
- Removing inactive subscribers
- Using a signup form with a good captcha system
By following these guidelines, you can prevent getting blacklisted and maintain a strong email list, which is necessary for successful email marketing campaigns.