Grant Cross-domain Access to an Exchange Resource

In order to grant a cross-domain access to a mailbox on another domain:

1. Remote into the Exchange server serving the domain that hosts the Mailbox
2. Open the "Exchange Management Shell"
3. Run the following power shell command:
   • Add-MailboxPermission -Identity <mailbox> -User <domain>\<username> -AccessRights FullAccess -InheritanceType All
   • Where <domain>\<username> is the user's domain and login name without the angle brackets
   • <mailbox> is the resource you are granting them access to

In order to grant a cross-domain access to a user's calendar on another domain:

1. Remote into the Exchange server serving the domain that hosts the calendar
2. Open the "Exchange Management Shell"
3. Run the following power shell command to view existing permissions:
   • Get-MailboxFolderPermission -identity <username>:\"Calendar\<Calendar Name>"
   • Where <username> is the exchange alias of the owner of the calendar to be shared.
   • <Calendar Name> is the name of the calendar to be shared. If the calendar to be shared is the default calendar, leave calendar name blank, and omit the preceding slash.
4. Run the following power shell command to add users to a calendar:
   • Add-MailboxFolderPermission <username>:\"Calendar\<Calendar Name> -User <domain>\First.Last -AccessRights Reviewer"
   • Where <username> is the exchange alias of the owner of the calendar to be shared.
   • <Calendar Name> is the name of the calendar to be shared. If the calendar to be shared is the default calendar, leave calendar name blank, and omit the preceding slash.
   • <domain>\First.Last is the other domain's user's domain and login name without the angle brackets.