WLM2012 does work fine with W10 as long as you use POP or imap for hotmail, outlook, live mail accounts.
I switched my setting when Microsoft sent out a mail a long while ago trying to talk people out of using WLM and to use the crap Windows10 mail or purchase the latest office including outlook.
No problems since.
Still on DeltaSync here with WLM2012/W7, and 6 different Hotmail accounts which all still work. Touch wood.
Any way to determine if you have been updated? I know in the past you could go to Outlook.com and if you got the splash screen and it says Outlook Mail instead of Outlook Preview then you were updated. That has happened to all my accounts. Is there still something to be updated and if so how will I know when it is done? I am currently using WLM 2012 with the update that came out in December 2015 and I am still syncing just fine Mail, Calendar, and Contacts.
That's supposed to be the way, if it says Outlook Mail then the account has been upgraded. Mine says Outlook.com.
The update which was pulled was/is supposedly only working with upgraded accounts.
In my experience using the email accounts provided by ISPs causes problems sooner or later. Such accounts typically have a lower capacity than Gmail or Outlook.com accounts; for instance one of my customers was using Verizon email account with a 250 megabyte limit, which is ridiculous by today's standards. There is also the problem of losing ISP email accounts when you decide to change providers. For that reason it's much better to use email that is independent of the provider.
My ISP doesn't do email....
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