I've also heard that win10 does some mucking up on people's web-based emails, but that's just hearsay and I'm a smug OS X user.
For mobile phone email - use an email client such as Mozilla.com (thunder...something). I migrated off of gmail and use outlook.com and have nothing more than the occasional and usual microsoft bloatware issues, but no firewall issues connecting sans vpn. For IOS, there's a FREE outlook email client. For desktops, outlook comes with all incarnations of MS Office since before some posters were born.
One last thing - when downloading applications for mobile or desktop/laptop/ipad, be absolutely certain of the source. The outlook clients should ONLY be downloaded from microsoft.com and select, known mirrors. Ignore the internet crap that says the app was certified and scanned virus/trojan free etc. ANYONE can write that stuff.