Open Exchange Management Shell and execute the New-Mailbox cmdlet using the following example as a template:
New-Mailbox -Alias "MySharedMailbox" -Name "My Shared Mailbox" -Database "MAIL1\First Storage Group\Mailbox Database" -OrganizationalUnit "mikefrobbins.demo/My OU/Users/Mailbox" -Shared -UserPrincipalName "firstname.lastname@example.org"
The following cmdlet assigns full access for the mailbox to a group in Active Directory named “My Shared Mailbox Admins” which needs to exist in AD prior to executing this command:
Get-Mailbox -Identity "My Shared Mailbox" | Add-MailboxPermission -User "My Shared Mailbox Admins" -AccessRights "FullAccess"
This cmdlet allows members of the “My Shared Mailbox Admins” group in Active Directory to be able to send email from the “email@example.com” email account:
Get-Mailbox -Identity "My Shared Mailbox" | Add-ADPermission -User "My Shared Mailbox Admins" -AccessRights: ReadProperty, WriteProperty -Properties "Personal Information" -ExtendedRights "Send-As"
Once these steps are completed, any AD user who is added to the “My Shared Mailbox Admins” group in AD will be able to open the “mysharedmailbox” and send email from this account.