According to the Rackspace Email & Apps System Status page:
Emergency Maintenance - Hosted Email
We will be performing an emergency maintenance to enhance the systems responsible for managing our hosted email platform. The maintenance window will begin Tuesday February 5th, 2019 at 8:00PM CST and end at 10:00PM CST.
While all measures are being taken to prevent any impact to users, some may experience a brief disruption of service during the maintenance window in Webmail ONLY such as:-Uploading and sending Attachments
-Resuming Drafts with already uploaded Attachments
-Viewing/Updating Contact Image
We encourage administrators with users experiencing issues once the maintenance window concludes to contact their Support Team for further troubleshooting.
Please continue to check my blog for service updates. As soon as I become aware of an issue that may impact your website or email, I will post it here. Thank you!