You may find that when you run the Exchange Hybrid Configuration Wizard that it does not run. If you launch it from Exchange Admin Center, or from the Exchange Online Admin Center, it may just flash up and do nothing.
The solution is to change the file association for .application files to Internet Explorer. However, if you try in the Control Panel, you will find that this is impossible:
The solution is to do this using good old Windows Explorer.
Check you are viewing file extensions in Windows Explorer (View > File name extensions)
Right click in your Documents folder or somewhere, create a new file called test.application
Right click on it and choose Properties, and change the application to Internet Explorer
Both mailbox creation and deletion failure scenarios heavily involve verifying the current recipient type values across all directories – especially in a directory synchronised environment. For example; if a user is listed on-prem as a remote mailbox with a cloud archive, then you should expect EXO to have a primary and an archive mailbox for this user. If it doesn’t, then troubleshoot for a synchronisation failure somewhere between on-prem and EXO.
The three attributes you will be dealing with are the following, and there are many possible values for each:
RemoteRecipientType (in PowerShell)
Note: You should only see the above value populated if the customer has a directory sync’d environment, and they either migrated a mailbox to the cloud or if they used new-remotemailbox to provision a cloud mailbox.
During a recent Office365 migration, one of the questions that arose was what would happen to Outlook Autocomplete entries (also known as the Nickname cache) when migrating users from on-premise Exchange, to Office365. Many users rely on this list, and a common complaint when this goes missing is ‘my contacts have disappeared’. In fact users just often don’t use contacts because it requires manual steps to save someone’s details, they just rely on the fact that once they have emailed a user, Outlook remembers the name and they just have to start typing it and Outlook completes the address for them.
The answer, as with many things in IT, is ‘it depends’. Largely it depends on the Outlook client version.
Outlook 2010 and later store the autocomplete list in a hidden folder in the user’s mailbox. The great thing about this is that when setting up a new PC if the user opens the same mailbox then the list will be there already as soon as the mailbox is opened. So when migrated to Office365, this hidden folder is migrated along with the user’s email. When they login to their mailbox through Outlook, it should be available.
Also note that Outlook Web App uses its own auto complete list, this is not the same as the one used by Outlook.
One final thing to note, is that if users autocomplete list is lost or accidentally deleted, one way of repopulating it is to draft an email with all of the users contacts in, and save it (but do NOT send!). This adds all of the addresses to the cache.
See ‘Information about the Outlook AutoComplete list’
How to fix issues synchronising and displaying emails in secondary or shared mailboxes in Exchange Online.
When migrating from Exchange on-premise to Office 365, users can experience issues displaying emails in secondary or shared mailboxes. When their mailboxes were hosted on-premise, users didn’t have this problem, since the Exchange servers were nearer to the users and Outlook could operate in online mode without experiencing the cached mode limitations.
Microsoft recommends 3 potential fixes for this issue:
Delete folders to reduce the folder count. This is often not possible since data needs to be retained, or needs to be separated into folders. Or there may just be so many additional mailboxes that it is not practical to have less than 500 folders across all of them.
Turn off cached mode for shared folders as below. However. since you Exchange servers are now in the cloud, whilst changing this setting will show all of the emails, not only will you be unable to access the emails when offline, but performance will be heavily dependent on network conditions. Frequently this will cause performance problems with Outlook; whilst these shared mailboxes were hosted on an on-premise Exchange server, moving them to the internet can make it too slow to access them in Online mode.
The solution is, therefore, the third recommendation by Microsoft. We recommend that clients skip the first 2 workarounds, and implement this from the start for any power email users who access a number of shared mailboxes. Unfortunately, this will require manual configuration by the end user, so a combination of automapping and manual configuration may be a good compromise.
Disable automapping for each secondary mailbox as per 2646504 – ‘How to remove automapping for a shared mailbox in Office 365’.
Add the account as a secondary account into Outlook via the Add New Account dialog box in Outlook. Simply add the email address of the account, as long as you have full access then it will allow you to add the profile.
Note that when diagnosing this issue it is very useful to use the Get-MailboxFolderStatistics cmdlet, which you can use to calculate if the user is near or over the 500 folder limit across all of their mailboxes.