Powershell commando’s If you need to give Send As Permissions to a User in Office 365, it can be done using a few simple commands in Exchange Online PowerShell. Send As permission is used when you need to give a user permission to use another recipient’s email address in the From address. First connect to your Office 365 tenant, using Windows PowerShell. To connect to Exchange Online, just start a PowerShell session and type in following commands: $Cred = Get-Credential The above command prompts you, for your Office 365 tenant admin credentials, it is important to enter as UPN format, such as e.g. admin@contoso.onmicrosoft.com. Next, we will create a new remote PowerShell session using the following cmdlet: $s = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://ps.outlook.com/powershell -Credential $cred -Authentication Basic –AllowRedirection Next we import of the PowerShell session: Import-PSSession $s You are now connected to Exchange Online with your Office 365 Tenant admin and can use Exchange Online PowerShell cmdlets available. Next grant a user permission to access another user’s mailbox, so they have permission to open it: Add-MailboxPermission -User -AccessRights FullAccess Then give Send As permission to users, som they can send as the user: Add-RecipientPermission -AccessRights SendAs -Trustee Bijvoorbeeld: Add-RecipientPermission support@xyz.nl -AccessRights SendAs -Trustee mailer-daemon@xyz.nl