If Outlook is your company's email provider... the third parties are the concern of your IT department.
If you're not hit by one of those two conditions... why are you using Outlook? This feels like unwarranted outrage bait.
Still your concern given whatever information is shared about you and your job to the 766 third parties.
I'm also thinking of 2FA things many corporations mandate, requiring the use of a phone number, application or both, without them handing you a work phone. Under no circumstances will I give my personal phone number to Google or Microsoft because I don't want them to link my work and personal stuff. Right now, I'm locked out of a corporate account at Google due to such refusal.
Bonus point if you get your own domain. Bitwarden and others allow creation of individual users on the fly on your domain, while a catchall on the email server collects this.