Meeting Rooms booking is not working or getting a bounce back message when sending email from group mailbox?
You need to exclude these mailbox resources from Xink ReRouting rule.
Login to Office 365 admin or Exchange admin portal go to "mail flow" find Xink-Auto-ReRouting-Catcher and edit it as shown below.
Edit the configuration as per the screenshot below and then add meetings rooms, calendaring or shared mailboxes as follow.
1. Except if "sender is = type 'meeting room' and recipient = type 'meeting room' and
2. Except If The message type is 'calendaring', leave the rest a default and then click Save.
Note: You may also apply this solution if you are getting bounce-back messages or having a problem sending or receiving emails on a particular service account or mailbox. You can you also exclude those mailboxes from getting rerouted by Xink-Auto-ReRouting-Catcher