Back to blog

Send as an alias in Microsoft Office 365

May 15, 2012 by Emma Robinson

Unfortunately in Microsoft Exchange 2010 and therefore Office 365 you are unable to send from any email address other than your primary email address, even if you can receive email from multiple email addresses.  If you try to send from another email address attached to your account you will get the following error:

You can’t send a message on behalf of this user unless you have permission to do so. Please make sure you’re sending on behalf of the correct sender, or request the necessary permission. If the problem continues, please contact your helpdesk.

There are two ways around this.  One is to set up a fake POP3 connection in Outlook.  This is kind of messy and only works from Outlook.

This blog here should help you.

The other option is to set up a new distribution list with the email address you want to send and receive from.

Read more Optimizing PowerShell for large Office 365 tenants

Firstly, create a new Distribution List in the Microsoft Office Portal by clicking the Distribution Groups link in the Admin section of the portal. For this example we will be using the email address

New Distribution list for

You can see that I have given it the name newsletter and added myself as an owner.  By default, new Distribution Lists will only accept emails from other people inside your organization.  You can change this by double-clicking the newly created Distribution List in the Exchange Control Panel and changing the delivery management options

Distribution List Delivery Management

Now that we have set up this new distribution list we can send a test email to from my Gmail account and it is received in my Office 365 mailbox.

Email Received to Custom Address

Finally, we have to give my user account send as rights to this new distribution list.  This has to be done by using Powershell to connect to Office 365.

Once you are connected to Office 365, you need to run the following Powershell cmdlet.  Obviously, you will need to substitute the email addresses for your own.
Add-RecipientPermission -AccessRights SendAs -Trustee

You will be asked to confirm your command, and then shown a summary of the permissions which were set.
PS C:\> Add-RecipientPermission -AccessRights SendAs -Trustee
Are you sure you want to perform this action?
Adding recipient permission 'SendAs' for user or group '' on recipient ''.
[Y] Yes [A] Yes to All [N] No [L] No to All [?] Help (default is "Y"): y
Identity Trustee AccessControlType AccessRights Inherited
-------- ------- ----------------- ------------ ---------
Cogmotive Newsletter alan Allow {SendAs} False
PS C:\>

Now that this is set up, you need to wait 15-30 minutes for this all to replicate.

After that, you can open up Outlook or Outlook Web Access and use the address as your From address.

To show the From field in Outlook 2010, create a new email message click the Options button at the top followed by the From button.

You should then see the From field in your new email message.

Send button in Outlook

Click this From button and select the Other Email Address option.

Make sure you select your Distribution List from the Address Book

The important thing here is to make sure you select the distribution list from the Address Book, don’t just type the email address in.


You can do the same thing in Outlook Web Access by creating a new email, clicking the Options button at the top and then ticking the Show From button.

Here you have it, an email from your address.

Email Received from our Custom Address

If you found this blog post useful, and want to refer to it again, why not download it as a PDF?

Related Posts

These other blog posts may be of interest to you: