Many organizations have migrated their email environments to Office 365 or plan to do so. Some of these have email in queue today and wonder if this functionality will work after the migration. The answer is yes and no.
In Office 365, mailboxes are moved between databases behind the scenes. This happens automatically and leads to the integration service losing its subscriptions on the monitored mailboxes that were moved. The service will not receive a notification that this has happened. To resubscribe the service needs to be restarted. New email that arrived between the time that the service lost the subscription and restart will not be queued and will have to be picked up manually. While the service can be configured to restart automatically at an interval there will therefore allways be a chance that some email have not been queued.
We are now working on a new connector for Office 365 and Exchange 2016 that will solve these issues.