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

Problem:

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

Solution:

Using Windows PowerShell, you can delete a client-side signature from OWA 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 signatures in OWA, users can create such signatures again, after you delete them.

To delete signatures from OWA, follow the steps below:

1. Connect to your Exchange Server:
   • Use the  Exchange Management Shell to connect to an on-premise server.
   • If you are using a remotely managed Exchange server, connect to it by following steps outlined in this article.

2. Use the following cmdlet to delete an OWA signature of an individual user:

Set-MailboxMessageConfiguration -identity "user’s UPN or alias" -SignatureHtml "" -SignatureText "" -SignatureTextOnMobile ""

3. 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 ""}

4. 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 ""}

5. 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:

• Additional information about the Set-MailboxMessageConfiguration cmdlet on Microsoft's website
• How to disable adding signatures created in OWA for Exchange users
• How to disable adding signatures created in Outlook for Exchange users
• How to delete a user's mailbox content