[TenFour]

Based on this post and other recent posts, Jeffpan, you have used and apparently continue to use many different email services. You must see some benefit in using multiple services, instead of one of your Top 5 services. Why not switch everything to G Suite or Fastmail if they are superior?

Ankupan: I use Microsoft 365 at my business, but it is mainly for the included desktop Office apps and the online storage in OneDrive and Sharepoint. Microsoft Office apps are the standard for business use and just about required for many business uses, so we might as well use the included email system. It is reliable, generally easy for people to use, and secure. However, IMHO Gmail/G Suite email provides better spam and phishing filtration, and is even more reliable, secure, and easy to use! For example, recently some really basic phishing messages regularly arrive in our Microsoft Inboxes. Some appear to be from internal emails until you dig into the email headers. Have not encountered that with Gmail. On the other side of the coin, every day I must scan the Junk folder with Microsoft email because it puts all sorts of things there from trusted and regular senders.