[hatfortguy]

You could try Protonmail. It's secure and supports GPG out of the box.

They have a free tier that they run as a "charity case". As with anything where your data _isn't_ the price, they have paid tiers too.

[hatfortguy]

I realize that doesn't answer your question about 365, but I meant to simply let you know there are good privacy friendly paid services too :)