Recently ran into an issue where a user reported that the list of available rooms always reported as 'None' in Outlook's Room Finder. Room Mailboxes were added correctly via the SolidCP portal, and the Room Mailboxes themselves populated correctly in the Address List. View from Outlook:

Changing the time around did not change the list of available rooms, despite those rooms being available (they were new and had no appointments at all). Digging into it a bit, it appears you have to create a Distribution Group that's a Room List. This allows you to select the Room List from a corresponding drop-down menu in Outlook:

https://docs.microsoft.com/en-us/exchange/troubleshoot/calendars/conference-rooms-not-displayed

So, we created a Distribution Group in SolidCP, however there is no option to make it a Room List - we had to convert it to a Room List using EMS on the back-end. Furthermore, you must add the Room Mailboxes as members of this Room List Distribution in order for them to populate as available in Outlook. Currently, it doesn't appear we can add Room Mailboxes to Distribution Lists via SolidCP either. As such, any time a customer makes a Room and has users who utilize Room Finder, we have to add it on the back-end rather than them just doing it themselves.

Has anyone run into this before? Are there plans to add a 'Room List' option for Distribution Groups and allow adding Room Mailboxes to them so users can manage these via the SolidCP portal?

For the record, we attempted to make a Dynamic Distribution with a filter for RoomMailbox recipient types and convert it to a Room List as a workaround. No go. Microsoft doesn't support that. Additionally, we attempted to make a Distribution Group a Room List, and then add a Dynamic Distribution list as a member to said Room List. No go on that either. Again, not supported.