If you're talking about the 'New Outlook' there is nothing you can do directly. It is NOT possible to automate the New Outlook in any manner.
We've asked the Access Dev Team about this for months, if not longer, and they have never given any workarounds to date.
Therefore, you have to look to switch to use
- CDO Mail
- Thunderbird email client which can be automated to send emails
- Automate the Microsoft Outlook Graph API
- Create your own REST API
- Or some other alternative approach
The whole thing is a mess and for the average developer a little bit overwhelming. This is why I've been advising my clients to hold off switching to the 'New Outlook' for as long as they can.
I'd also urged you to send your feedback about your experience and how it has affected you via their feedback mechanism!