We will be adding some new drives to Mail5 on Sunday Feb 21st at 4pm GMT.
The downtime should only be a few minutes and we will update this ticket when the work is completed.
Update (4pm GMT): The server is going down for scheduled maintenance.
Update (5:20pm GMT): The new drives have been added. While adding them we noticed a degraded drive and are replacing it now.
Update (6pm GMT): Done
Update (6:26pm GMT): The server is under high load as it is catching up for the time it was down. We will continue to monitor the server until it normalizes.