However, gmail is going to start charging for email.
From Hacker News:
So with Google starting to charge previously-free users, I've decided that I'd rather give my money to someone else. I'd like a provider who is likely to be around in a decade or two. Tips on moving many years of Google email to a new provider are appreciated as well!
The upside of this is
that there are lots of articles discussing different (free) email providers, hopefully, with enough information to help you, and not at a high tech level. Some articles linked below.
Outlook, as you stated above is an application, and as such, should be able to connect to any mail server (that uses IMAP protocol)
Just think "Alternatives to Cox" when you see "Alternatives to Gmail"
This list seems more than enough: I made it real short. The articles have more, if you want.
Zoho Mail
Outlook
iCloud Mail
Yahoo! Mail
Don't be confused: Microsoft offers an email service called outlook.com (no doubt to capitalize on the popularity of the outlook app) Outlook.com used to be hotmail, which they bought.
Of these, the most common might be outlook.com, iCloud Mail (you don't have to be an apple user, IIRC) and Yahoo
All that I have used also work via a web browser, which helps a lot when you are away from home.
And all should work with iPhone and Android "mail" apps, or they may have their own mobile app.
Just check before switching.
For details, see these links:
https://themeisle.com/blog/gmail-alternatives/
https://www.rightinbox.com/blog/alternatives-to-gmail
The article below focuses on privacy
https://restoreprivacy.com/email/alternatives-to-gmail/
If she wants to transfer existing emails from Cox to another provider, that can be
really complex (see the Hacker News article and have a computer nut read it and do it)
https://news.ycombinator.com/item?id=30223538
HEY FOLKS, if I got any of this wrong, please let me know, and I'll correct it.