Not to hijack - still relevant to this thread.
Reliability and this worry with silent filtering is the biggest thing that sticks in my craw as has been discussed before.
I use a MacBook Pro at home, iPhone on the go, iPad occasionally. May or may not return to Windows some day but being platform-agnostic is not a huge thing to me.
Currently use iCloud for everything -- mail, contacts, calendars, notes, tasks, some Pages/Numbers/Keynote use, pictures. Seamless with OS X and iOS. I prefer simplicity and like one service. Cons regarding mail as above.
Am thinking about going to Outlook.com for mail and solely mail while keeping everything else with iCloud. Gain badge updates, lose active connection on desktop (no IMAP IDLE) which is less of an issue and may be a non-issue if platform unification as above includes Exchange support for Outlook.com accounts. Supposedly would be more reliable(?) than iCloud but am unsure. Don't know how much or often blacklisting is an issue -- or if senders receive notifications of non-delivered status.
The alternative would be to migrate everything to Outlook / OneDrive. Lose Pages/Numbers/Keynote seamlessness (have not explored the Office 2016 beta or Office 365), custom fields in iOS contacts, etc.
Anyone have any strong feelings for pros/cons to this?
I don't see your concerns as hijacking as they're pretty strong concerns - and the OP has been MIA since the first post anyway...
I like O365 (the Business version) since I can order 1
license at a time - IMO the "politically correct" or "millenial" term for "CAL" or "client access license" - and not have to worry about investing in any more corporate products, because I don't need that much power. That's what Salesforce is for, if I need it, and I've read that MS is looking to buy them too.
The only "powerful" feature in O365 that I use and really like is whitelisting/blacklisting of users or domains or IP addresses from my web admin portal - and I REALLY like that.
IMHO any time one subscribes to a free email service you'll have to deal with "the IT guy in the sky", and that's why I *never* use Gmail/iCloud email/Outlook.com email for anything important. FWIW, it's really a shame that MS stopped allowing for the creation of free custom domains on that platform, opting to upsell to O365. But, that aside, IMO I accept that some IT guy is blacklisting as they see fit for those free accounts.
You can also roll your own, using one of the dynamic IP companies like No-IP or afraid.org, both of which have free and low-cost sub-domain services, and use them with your existing Mac clients or the Server app or with MAMP Pro. I'm considering rolling my own with my Mini Server, but I can also use a custom domain with my personal O365 account and filter my own inbox.
FWIW, if you're considering O365 you can pay the $6 per month to MS or buy a Business Premium 1-year card (which has a 25-digit key code) from Amazon for about $75, and the BP option has email plus 5 installs of Office (which you can share so long as the installs are registered in your O365 Portal).
Gotta run! Cheers!