You can configure Outlook to send all your mails with a "High Priority level", here's how:
- Open Outlook
- Click on File > Options > Mail tab
- Scroll to the "Send messages" section
- Next to "Default Importance level" select "High"
This document, titled « Outlook - Set the default importance level of your emails », is available under the Creative Commons
license. Any copy, reuse, or modification of the content should be sufficiently credited to CCM