Knowledge Base

How to delete OWA (Outlook on the web) signatures in Microsoft Exchange

Problem:

You want to remove OWA (Outlook on the web) signatures of multiple or individual users.

Info

The solution below only applies to Microsoft Exchange Server 2010, 2013, 2016, 2019 and Microsoft Exchange Online (Microsoft 365).

Solution:

Important

Before running the commands listed below, 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).

Using Windows PowerShell, you can delete a client-side signature from Outlook on the web from any user in your organization. The email signature is deleted from the target users' OWA settings, so that this client will no longer add those email signatures automatically and a user will not be able to add the OWA signature manually, using the built-in option. It is especially useful if you manage your email signatures centrally and want to avoid double signatures from users who use OWA as their email client. Mind that unless you disable adding email signtures in OWA, users can create such signatures again, after you delete them.

To delete signatures from Outlook on the web, follow the steps below:

  1. Connect to your Exchange Server:
    • Use the ems Exchange Management Shell to connect to an on-premise server.
    • If you are using Exchange Online (Office 365) or a remotely managed Exchange server, connect to it by following steps in this article.
  1. Use the following cmdlet to delete an Outlook on the web signature of an individual user:
Set-MailboxMessageConfiguration -identity "user’s UPN or alias" -SignatureHtml "" -SignatureText "" -SignatureTextOnMobile ""
  1. Run the following cmdlets to delete OWA signatures of all members of a specific distribution group:
$groupmembers = Get-DistributionGroupMember "distribution group name" -ResultSize unlimited;
$groupmembers | foreach { Set-MailboxMessageConfiguration -identity $_.alias -SignatureHtml "" -SignatureText "" -SignatureTextOnMobile ""}
  1. Execute the following PowerShell cmdlet set to delete signatures from OWA settings of all users:
$mailboxes = Get-Mailbox -ResultSize unlimited;
$mailboxes | foreach { Set-MailboxMessageConfiguration -identity $_.alias -SignatureHtml "" -SignatureText "" -SignatureTextOnMobile ""}
  1. You can also disable automatic signature adding in OWA:
$mailboxes = Get-Mailbox -ResultSize unlimited;
$mailboxes | foreach { Set-MailboxMessageConfiguration -identity $_.alias -AutoAddSignature $false -AutoAddSignatureOnReply $false}

See also: