Rackspace Email Issues

Positive test results have confirmed that this issue is resolved.

Our team has identified the cause of this incident and have applied a configuration change. We are now seeing positive results. Users that may have sent emails during the time of the incident may still receive the error until they have processed. Newly sent emails will be sent successfully. We will continue to monitor the issue and provide additional updates as they become available.

We are aware of an issue users are experiencing when sending from our Hosted Email environment. Affected users will receive the error "451 4.3.5 Sender address rejected: Server configuration error" when attempting to send via email clients (such as Microsoft Outlook), Webmail and mobile devices. There is no effective work around for sending email at this time. This issue will only affect outgoing email. Incoming email delivery is working as normal.