Gal not updating automatically
Instances of mail that is bounced back to the sender may also be fixed.
Please use the steps below to update your Global Address Book.
Although all parameters for this cmdlet are listed in this topic, you may not have access to some parameters if they're not included in the permissions assigned to you.
To see what permissions you need, see the "Address lists" entry in the Email address and address book permissions topic.
By default in Exchange Online, the Address List role isn’t assigned to any role groups.