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How to add additional email addresses and alter the primary?

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Our federated users currently have two email addresses associated with the Office 365 mailbox:

- their UPN from the active directory

the address that is auto generated by the Online Services.

We have already added and verified our company's actual email domain and now need to add email addresses in this domain to the federated IDs and make these email addresses the primary ones. Since these IDs are federated we cannot add the email addresses in the Online Services admin tool and our active directory does not allow us to specify them either.

Please not that we plan to use Office 365 exclusively (i.e. there will not be an internal Exchange org), but I suspect that we will have to at least implement the Exchange 2010 schema to be able to add additional email addresses to the AD users. What else do we have to put in place to be able to add email addresses to our AD accounts?


Thanks and regards,


All Replies
  • Andy,

    I don't believe this is going to be possible with federated users, based on the following information:

    Federated users are treated the same as normal users.  However, there some implications when dealing with Federated users, such as:

    • You cannot edit user properties that are synchronized by using Directory Synchronization in the Microsoft Online Portal (MOP).
    • You cannot edit Federated user properties when the user account are uploaded to MOP without using DirSync.
    • You cannot create a user in a federated domain by using the MOP.
    • You cannot move a user from a managed domain to a federated domain. This means you cannot change the domain part of the UPN of a Managed user to a Federated domain.
    • You cannot rename a user that resides in a federated domain. This means you cannot change the alias or domain that is in the UPN of a Federated User.
    • You cannot reset a federated user’s password.  
    • You cannot reset a federated user’s password during the activation process  or the license assignment process.  




  • Chase,

    I understand that I cannot add the email address and make it the primary in the Online Portal, but how can I do it in my local AD?



  • I guess the answer depends.  If you have Exchange, then you would open the Exchange MMC --> Email Addresses and either create or select the proper email and set as Reply To

    If you don't have Exchange, you can use ADSIEdit to modify this person's proxyAddresses attribute, which when using DirSync will push the user's Primary (Upper case SMTP) email address into EXO365 and this will be used as the Reply To address when sending mail from EXO:

    Note - If you are using Federation, you are using DirSync so you MUST modify these settings on-premises.

  • Ryan,


    Your instructions work great for adding an alternate email address... except that I cannot add an email address that uses the alias.


    The issue I am dealing with is best described by this forum post: Essentially, because our UPN suffix does not match our primary email address when the user is DirSynced over to Office 365, the user account is not being assigned an email alias when it is created.


    Little more background:

    * Our public domain name is

    * Our AD forest containing our Office 365 users is

    * This AD forest has a two way trust with another AD forest which has a domain name that matches our public domain name:

    * Thus, we cannot simply add an alternate UPN suffix of to the domain In some environments, the alternate UPN suffix could be a workaround... but it wouldn't work here.


    Here's what I'm dealing with:

    * Because this is a DirSynced/Federated user, I can't use the Office 365 administration portal to add the alias to the account --- as mentioned above, you can only add aliases using the Exchange MMC / proxyAddresses attribute.

    * If I add a proxyAddress to the user account in AD with the format:

    and force a DirSync, Exchange Online ignores the address.


    So... how am I supposed to add a email alias for an existing DirSynced/Federated user? I'm really hoping to avoid the procedure mentioned in the other post: deleting the user and recreating them with the UPN, mail attribute, and primary proxyAddress attribute all being equal. Then, DirSyncing them to Office 365 and activing the user (user gets created with the alias). Next, I edit the user in AD to change the mail attribute and the primary proxyAddresses attribute, force a DirSync, and the user shows up with the correct primary email address and still has the alias. Sure, this process works, but it sure is messy.


    Let me know your thoughts. Thanks!