552 mail rejected by the processing module 5.1.1

A common error!

The error "552 Mail rejected by the processing module 5.1.1" typically indicates that the email you're trying to send has been rejected by the recipient's email server due to a problem with the email itself.

Here are some possible reasons for this error:

  1. Invalid email address: The recipient's email address may be invalid, non-existent, or not properly formatted.
  2. Email content issues: The email may contain invalid or malicious content, such as viruses, spam, or phishing attempts, which is being blocked by the recipient's email server.
  3. Size limitations: The email may be too large to be sent or received by the recipient's email server, which has size limitations.
  4. Authentication issues: The email may not be properly authenticated, which can cause the recipient's email server to reject it.
  5. Blacklisting: The sender's IP address or email server may be blacklisted, which can cause the recipient's email server to reject emails from that IP address or server.

To resolve this issue, you can try the following:

  1. Check the recipient's email address: Ensure that the recipient's email address is valid and properly formatted.
  2. Check the email content: Review the email content to ensure it's not malicious or contains any sensitive information.
  3. Check the email size: Ensure that the email is within the size limitations set by the recipient's email server.
  4. Check authentication: Verify that the email is properly authenticated using SPF, DKIM, or DMARC.
  5. Check blacklisting: Check if the sender's IP address or email server is blacklisted and take steps to resolve the issue if necessary.

If you're still experiencing issues, you may want to contact the recipient's email administrator or IT department for further assistance.