We have an on-premise Exchange server and have installed a hybrid server and the Windows Azure directory synchronisation tool. This is all working as expected.
When we are migrating users, some are highlighting that they can no longer access calendars, mailboxes, use send as and send on behalf of facilities of users which are on the on-premise Exchange server and vice versa.
I know from a previous post that Microsoft have stated that cross-site permissions are not supported and that during the migration, these permissions would not be automatically preserved, however it was my understanding that the permissions could be manually applied. We even had a script which extracts all of the permissions to help with this process.
After migrating a few other users who had access to on-premise mailboxes and resources, they can no longer access / use these resources despite us applying the correct permissions via the relevant PowerShell commands. We have migrated other users before and applied the permissions afterwards and that has worked.
After speaking with Microsoft, they have just re-stated that cross-site permissions are not supported. However, if this is the case then why would previously migrated mailboxes for other users work when we have manually applied the permissions? When this was challenged, Microsoft stated 'it may work initially, but then may drop-off' later on. This doesn't make any sense to me.
They have further stated that you have to migrate every user who use each others resources together. What is the point in having a hybrid server if migrated mailboxes cannot be migrated in phases when restricted by common resource access?