Obviously I want you to use @thunderbird, but whatever you do, please STOP using #Outlook!
https://proton.me/blog/outlook-is-microsofts-new-data-collection-service
"Everyone talks about the privacy-washing (new window) campaigns of Google and Apple as they mine your online data to generate advertising revenue. But now it looks like Outlook is no longer simply an email service(new window); it’s a data collection mechanism for Microsoft’s 772 external partners and an ad delivery system for Microsoft itself."