Users of email via a browser, Thunderbird, Kmail, Mutt, Apple Mail or whatever probably won't be interested in this. To be fair, neither (probably) will users of MS Outlook, but there you go. 

MS is going to roll out a new version of their email client, Outlook. I've used Outlook for years, currently on the MS 365 version. It's OK. Does some things well, others badly, some so so, much like many other clients I've tried. On Outlook with MS 365, the new Outlook is being offered for a try. You can toggle between old and new. Generally, your email sits on the server of whoever provides the service, whether it's an ISP, a company like MS, or even email from whoever hosts your domain. For instance, MS provides my hotmail account, so my email sits on an MS Server or servers somewhere. I use a client so I have local copies as well. 

But, with the new Outlook one thing is completely different. MS wants to sync any non-MS accounts you access via Outlook to the MS Cloud. As their online help makes clear -  The help implies that this "can" now be done by the user, and that it's an enhancement: a big opportunity etc. In fact, it "must" be done to use the new Outlook. Obviously, the old Outlook's days are numbered, so soon enough all non-MS email accessed through Outlook will be copied onto their servers.

Not sure I'm happy with this. OK, so I rely on Google to store copies of my email safely if I use GMAIL. Same thing with a handful of other accounts that I've yet to get rid of. But do I want Microsoft to hold yet another copy somewhere on the Cloud?

I don't use Outlook to access other mail accounts, but I do use Gmail to access Outlook, precisely because it offers a stripped down way to access work emails. Outlook is a slow, kludgy resource hog (like most of Office) with a ton of bells and whistles that I don't use, cluttering up the interface and bloating the code. I think it's really oriented to the corporate cloud user. Which I suppose I am. Ho hum.

You're quite right, of course. Worse still, functions and features that would be useful are often squirrelled away in ridiculously obscure and unlikely places. For example, I do some admin for a writers' group and regularly need to resend emails i.e. exact same email to the same or a similar list of people. So where is this obvious feature? Naturally it's on the taskbar when you open a previously sent email. But it isn't in with all the "sendy" options such as reply, reply all, forward etc. It's under "actions" in the "Move" group of commands. And that was one of the easier ones to find.

I quite like gmail, but I suppose I'm lazy and have grown used to Outlook. I also find that gmail's way of ordering conversations can get in the way a bit, although I confess I haven't checked on whether it can be changed.

> but I do use Gmail to access Outlook, precisely because it offers a stripped down way to access work emails.

O_o Has Outlook become so bad that Gmail is considered stripped down?

Actually, considering what Windows 8/10 are like, that shouldn't really be a surprise.

But what about Outlook Web Access? Last time I used that, I think it was more lightweight than even Gmail's "Basic HTML" interface (the one which is apparently going away in a few months).

OWA is pretty much the full Outlook these days, it's sort of impressive sort of stupid.

Thinking specifically of the android Gmail app. I avoid using the browser version.