The Outlook Web App in the new Office 365 is great, and is designed to work well in the latest versions of supported browsers.
Fortunately, Outlook Web App provides a “light” experience that works much better in older browsers, even if it is not as pretty.
I wanted to share a couple of easy ways for your users on older browsers to access the light version of OWA:
Set-OWAMailboxPolicy -Identity "Light OWA Users" -PremiumClientEnabled $False
Set-CASMailbox -Identity "[UserName]" -OWAMailboxPolicy "Light OWA Users".
Note: According to the Set-OWAMailboxPolicy documentation, the “-PremiumClientEnabled” parameter is deprecated, so… keep in mind that this is a near-term stopgap that will stop working in the future.
The best solution to the “old browser” problem is to move your customers off of the old browser and on to the latest versions of any of the supported browsers. If you are a Microsoft Partner with a Silver/Gold competency, work with a Partner Solution Consultant on your next Windows/IE upgrade project to help work through application compatibility problems that may be blocking upgrades.