Managing personal signatures, fonts and stationery for "New" Outlook and Outlook on the web
You wish to control internal settings for "New" Outlook or the Outlook on the web (OWA) client whilst using Signature 365.
As New Outlook and OWA are hosted on the Microsoft 365 Exchange platform, this must be configured using Exchange Online Powershell commands.
Use Exchange Online PowerShell cmdlets to set several options, or use a script to apply these options to all users on your Exchange Online server.
- If the Exchange Online Powershell module is not installed, open an administrative Powershell window on your device, type Install-Module -Name ExchangeOnlineManagement, and hit Enter.

- You will receive the following prompt - type "Y" to confirm and install.

- Log in to Exchange Online using your Global Administrator or Exchange Management credentials.

- You will see the following information when connected to Exchange Online.

User created signatures can be completely disabled for all users in OWA / New Outlook by using the following powershell command.
If you are not using the default mailbox policy, you must apply this setting to any custom policies you use.
Set-OwaMailboxPolicy -Identity "OwaMailboxPolicy-Default" -SignaturesEnabled $false
The following cmdlet is used to set message font with command line arguments:
Set-MailboxMessageConfiguration <username> <parameter>
Set new email font:
-DefaultFontName <Name>
Setting Outlook default font colour
-DefaultFontColor <Color>
Setting Outlook default font size
-DefaultFontSize <Size>
Setting Outlook default font style:
-DefaultFontFlags <Flags>
Where:
<Name>
Font name. If unrecognised, Calibri is used as default
<Colour>
Default colour code surrounded by quotes in RGB format. Default is #000000
<Size>
A integer between 1 and 7. Default is 3, corresponding to 12pt
<Flags>
Specifies the text effect, the following can be used:
- Normal
- Bold
- Italic
- Underline
- All
Example
Set font to Arial 12 point Bold black for new email:
Set-MailboxMessageConfiguration support@symprex.com -DefaultFontName Arial -DefaultFontColour "#000000" -DefaultFontFlags Bold
The following command line arguments cannot be used if Roaming signatures are enabled on your Microsoft 365 tenant.
Set HTML signature
-SignatureHtml
Set roaming text signature
-SignatureText
Example
To set default signature to blank:
Set-MailboxMessageConfiguration support@symprex.com -SignatureHtml ""
Managing personal signatures, fonts and stationery for Outlook Classic desktop
Use the Symprex Email Signature Utility to manage Classic Outlook fonts, stationery, and personal signatures on local devices.
Updating the Signature 365 Outlook add-in
Manually update the Signature 365 Outlook add-in when a major release requires redeployment through Microsoft 365 or manifest-based installs.