Why email bounce

Email bounces, also known as email non-deliverables, occur when an email message is unable to be delivered to the recipient's email address. There are several reasons why an email may bounce, including:

  1. Invalid or non-existent email address: The email address you're trying to send to doesn't exist or is invalid.
  2. Domain name system (DNS) issues: The DNS settings for the recipient's domain are incorrect or not properly configured, preventing the email from being delivered.
  3. Mail server issues: The mail server for the recipient's domain is down or experiencing technical difficulties, preventing the email from being delivered.
  4. Spam filters: The email is flagged as spam by the recipient's email provider or their ISP (Internet Service Provider), and is blocked or bounced.
  5. Email address blacklisted: The email address or domain has been blacklisted by the recipient's email provider or ISP, preventing emails from being delivered.
  6. Email attachment issues: The email attachment is too large, or the file type is not supported by the recipient's email provider.
  7. Email content issues: The email content contains viruses, malware, or other malicious code that is detected by the recipient's email provider.
  8. Recipient's email account is full: The recipient's email account is full, and the email cannot be delivered due to storage limitations.
  9. Email authentication issues: The email authentication settings (e.g., SPF, DKIM, DMARC) are not properly configured, causing the email to be rejected or bounced.
  10. Network connectivity issues: There are network connectivity issues between the sender's and recipient's email servers, preventing the email from being delivered.

When an email bounces, it's usually indicated by a bounce message or error message that is returned to the sender. The bounce message will typically provide information about the reason for the bounce, such as "Recipient's email address is invalid" or "Email attachment is too large."

To troubleshoot email bounces, you can try the following:

  1. Check the email address: Verify that the email address you're trying to send to is valid and exists.
  2. Check the email content: Ensure that the email content is free of viruses, malware, and other malicious code.
  3. Check the email attachment: Verify that the email attachment is not too large and is in a supported file type.
  4. Check the email authentication settings: Ensure that the email authentication settings are properly configured.
  5. Check the recipient's email provider: Verify that the recipient's email provider is not blocking or bouncing emails from your domain or IP address.
  6. Check the network connectivity: Verify that there are no network connectivity issues between the sender's and recipient's email servers.

By troubleshooting and resolving the underlying issue, you can reduce the likelihood of email bounces and ensure that your emails are delivered successfully.