Removing OWA signatures for multiple users

Relevant Products: Signature Manager Exchange Edition | Signature Manager Outlook Edition

Scenario

You need to remove OWA signatures for:

• All existing users, in a single operation
• An individual user

Resolution

You can remove multiple OWA signatures using Windows PowerShell commands, as summarized in the following sections.

Removing OWA signatures for all existing users

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, run the Exchange Management Shell.
   - For a remotely managed Exchange, make a connection using the steps detailed here, then return to this section.
   
   
3. Execute the following PowerShell cmdlet sets:
   
   
   $mailboxes = Get-Mailbox -ResultSize unlimited
   
   $mailboxes | foreach { Set-MailboxMessageConfiguration -identity $_.alias -SignatureHtml "" }
   
   - Here, SignatureHtml should be replaced with SignatureText or SignatureTextOnMobile for other signature formats your users might have configured.
   
   
4. If required, you can also disable the OWA signature auto adding feature without actually removing signatures (or you can combine the following command with the above to do both):
   
   $mailboxes = Get-Mailbox -ResultSize unlimited
   
   $mailboxes | foreach { Set-MailboxMessageConfiguration -identity $_.alias -autoaddsignature $false }

Removing OWA signatures for an individual user

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, run the Exchange Management Shell.
   - For a remotely managed Exchange, make a connection using the steps detailed here, then return to this section.
   
   
3. Depending on your operating system, run the commands below.

Exchange 2007

Execute the following PowerShell command:

Where <username> is replaced with the username for whom you wish to disable OWA signatures.

Exchange 2010, Exchange 2013 or Exchange 2016

Execute the following PowerShell commands to create a new OWA mailbox policy and then apply that policy to the required user:

Where:

• <username> is replaced with the username for whom you wish to disable OWA signatures.
• NoSig is the name of the OWA mailbox policy that we are creating.

Having run this once, you can then run the final command for any other required users:

How to set up a remote session to Exchange Server using PowerShell

If you use 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:
   - Exchange Server 2010
   - Exchange Server 2013
   
   
2. Run Windows Powershell.
   
   
3. Use the command below to check your execution policy settings:
   
   Get-ExecutionPolicy
   
   Here, SignatureHtml should be replaced with SignatureText or SignatureTextOnMobile for other signature formats your users might have configured.
   
   
4. If the execution policy is set to Restricted, change it to RemoteSigned or Unrestricted using the command below:
   
   Set-ExecutionPolicy RemoteSigned
5. Provide target server administrator credentials using the command below:
   
   $LiveCred = Get-Credential
6. 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
7. Start the connection using the command below:
   
   Import-PSSession $Session
8. When you have finished working and are ready to disconnect, use the command below:
   
   Remove-PSSession $Session