Hello,
We have a client who currently runs Exchange 2007 and has 2 organizations using it. (so 2 email domains). One of those organizations will be splitting off and getting their own Offfice 365. There wont be any hybrid setup the Office 365 will be fully cloud.
We have about 5 conference rooms here in the office which are setup as Room Calendars in the Exchange 2007.
Is it possible to somehow make it so users in the Office 365 can view those Exchange 2007 room calendars? Even better, is it possible for someone from the Office 365 to edit one of those Exchange 2007 calendars.
Last note, these would be two separate domains
On if it's possible to modify on-prem mailboxes from the cloud, not directly. If you have an on-prem mailbox that users add to their outlook profiles (with Outlook 2010+) they could open the calendar and edit it with that account, but there is no way to allow mailbox permissions for Office 365 mailboxes to On-prem mailboxes.