There is a team from both providers working on a solution. In the meantime, we recommend using the RoundCube version of webmail. This works with no issues.
To change from Horde to RoundCube, follow the steps below.
1) Log into your webmail as usual
2) Click the little drop down arrow in the top right hand corner next to your email address.
3) In the menu that appears, select RoundCube instead of Horde
Once the developers have a solution in place, we will let you know if you wish to switch back to Horde at that time.
Phoenix Hosting Technical Support Team
Friday, February 3, 2017