How to hydrate user accounts in OWA to avoid warning or error in Signature Manager Outlook Edition


In Signature Manager Outlook Edition, the following warning/error is displayed:

The user must sign in to OWA at least once to create the mailbox so that the signature and settings can be applied


For Signature Manager Outlook Edition to deploy signatures and settings to a user’s OWA account (for either Exchange or Office 365), the user’s profile must have been created in OWA. This is known as ‘hydrating’ a user’s account.

A user’s profile is hydrated the first time they log on to OWA and select their regional options. It is not hydrated when a user accesses their mailbox using an email client such as Outlook - they must log on to the OWA website itself for the mailbox to be hydrated .


To avoid the need for all users to log on to the OWA website so their signatures are deployed, you can use PowerShell commands to hydrate a user’s profile. To do this, follow the steps below:

  1. Ensure that you are logged in as a user who is a direct member of the Organization Management and Domain Admin groups (Global Administrator in the case of Exchange Online).
  2. Connect to your Exchange Server:
    • For Exchange on-premises, simply run the Exchange Management Shell.
    • For Exchange Online (Office 365) or a remotely managed Exchange, make a connection using steps detailed here, then return to this section.
  3. Once connected, run the following command to hydrate a user’s mailboxes:

  4. Get-Mailbox <user> | Set-MailboxRegionalConfiguration -TimeZone "<Time Zone>" –Language <Language>  -DateFormat "<Date Format>"    

    Replace <user> with the user’s account, <Time Zone> with the user’s timezone name, <Language> with the Language Culture Name, and <Date Format> with the required date format (retain quotes where shown).

    For example, for a user in the UK:

    Get-Mailbox | Set-MailboxRegionalConfiguration -TimeZone "GMT Standard Time" –Language en-GB  -DateFormat "dd/MM/yyyy"    

    For example, for a user in the US Central time zone:

    Get-Mailbox | Set-MailboxRegionalConfiguration -TimeZone "Central Standard Time" –Language en-US  -DateFormat "MM/dd/yyyy"    


Commands detailed in step 2 above show how to a hydrate mailboxes for specified users. However, if required you can hydrate mailboxes for all users, using the command below:

Get-Mailbox -ResultSize unlimited | Set-MailboxRegionalConfiguration -TimeZone "<Time Zone>" –Language <Language> -DateFormat "<Date Format>"

For example, if all of your users are in the UK, you can use the command below to hydrate mailboxes for all users:

Get-Mailbox -ResultSize unlimited | Set-MailboxRegionalConfiguration -TimeZone "GMT Standard Time" –Language en-GB  -DateFormat "dd/MM/yyyy"

If you have users in multiple different time zones, or that require different language options, you can use other input parameters available for the Get-Mailbox cmdlet to apply settings to a group or subset of users.

How to set up remote session to Exchange Server using PowerShell

If you use Exchange Online (Office 365) or a remotely managed exchange (Exchange Server 2010 or 2013), you need to set up a remote session to access the Exchange server. To do this, follow the steps below:

  1. Check system requirements for your operating system:
  2. Run Windows Powershell.
  3. Use the command below to check your execution policy settings:

  4. Get-ExecutionPolicy    

  5. If the execution policy is set to Restricted, change it to RemoteSigned or Unrestricted using the command below:

  6. Set-ExecutionPolicy RemoteSigned    

  7. Provide target server administrator credentials using the command below:

  8. $LiveCred = Get-Credential    

  9. Configure the connection using the relevant command below:
    • To connect to Exchange Server 2010 or 2013:

    • $Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://<target-server-address>/powershell/ -Credential $LiveCred        
    • To connect to Exchange Online (Office 365):

    • $Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri -Credential $LiveCred -Authentication Basic -AllowRedirection        

  10. Start the connection using the command below:

  11. Import-PSSession $Session    

  12. When you have finished working and are ready to disconnect, use the command below:

  13. Remove-PSSession $Session    

Signature Manager Outlook Edition How To Troubleshooting