This error message indicates we are seeing unusual traffic from your IP address and/or that emails from your mail server are generating complaints from Yahoo! Mail users. Please note that this is a temporary error, and we encourage you to retry sending emails to our servers approximately 4 hours after you encounter this particular error.

If you are seeing this error consistently over a 48-hour period, we encourage you to provide us with detailed information, including the complete error message you see in your logs, by filling out this form. (Note: Please make sure to select “Getting deferrals due to user complaints” in the form’s dropdown menu.)