If you have multiple versions of Microsoft Outlook (2011, 2016, 2019, 2021, 365) installed on the same machine, you can use the application to add a signature to either one. The latest version of the software will prompt you to choose which version to use.
For legacy versions only, follow these steps to control which version of Microsoft Outlook is used to create your signature.
- Close all open instances of Outlook
- Launch the version of Outlook you'd like to use
- Close Outlook again
- Create your signature. The most recently launched version (from Step 2) will be used.