Starting October 1, Microsoft will begin to randomize tenants and disable basic authentication access for MAPI, RPC, Offline Address Book (OAB), Exchange Web Services (EWS), POP, IMAP, Exchange ActiveSync (EAS), and Remote PowerShell. As you know, SMTP AUTH will not be affected by the changes made.
On the day of the change, Microsoft will notify each tenant through the Service Status Dashboard.
If you’re not ready to make these changes, You can do a One-Time Re-Enablement one last time as decided by Microsoft.
If you create your user’s mailbox directly from the Office 365 management console, you will not be able to see the newly created mailbox on your On-Premises Exchange server.
The recommended method is to create the mailbox on the On-Premises Exchange server.
In order to solve the problem of the mailbox created directly on Office365 not appearing on Hybrid Exchange in our scenario above, you should run the following commands on the On-Premises Exchange according to the mailbox you are having trouble with.
$uid = read-host "Please enter username" $mailnick = read-host "Please enter username" $tempmail = $uid+"@company.mail.onmicrosoft.com" $primarymail = $mailnick+"@company.com"