Client host rejected excessive mail use

The infamous "excessive mail use" error!

The "Client host rejected excessive mail use" error typically occurs when a mail server (e.g., Postfix, Sendmail, or Exim) detects that a client (e.g., a mail client or a script) is sending an excessive number of emails in a short period of time. This is often a security measure to prevent spamming or abuse of the mail server.

Here are some common reasons that may trigger this error:

  1. High volume of emails: Sending a large number of emails in a short period, such as during a mass mailing campaign or a script that sends emails rapidly.
  2. Frequent connections: Making multiple connections to the mail server in a short period, which can be indicative of a spamming or abuse attempt.
  3. Large email attachments: Sending emails with very large attachments, which can consume excessive resources on the mail server.

To resolve this issue, you can try the following:

  1. Check your mail client or script: Review your mail client or script to ensure it's not sending emails excessively or rapidly. Consider implementing a delay between sending emails or limiting the number of emails sent at once.
  2. Contact your mail server administrator: If you're using a shared mail server or a hosting provider, contact their support team to ask about their policies on email sending limits and to request an increase in your sending quota if necessary.
  3. Use a mail server with a higher sending limit: If you're using a mail server with a low sending limit, consider switching to a mail server with a higher limit or a more flexible configuration.
  4. Implement rate limiting: You can implement rate limiting on your mail client or script to slow down the sending of emails and avoid triggering the "excessive mail use" error.
  5. Check your email content: Ensure that your email content is not triggering spam filters or being flagged as spam, which can also lead to the "excessive mail use" error.

Remember to always follow the terms of service and acceptable use policies of your mail server and hosting provider to avoid any issues or account suspensions.