Apparently their ISP doesn't like Google, which confuses me, seeing as Google is basically an internet "need" at this point and I think any ISP would be foolish to interfere with the operations. I'd probably suggest having a look at the router settings.

yandex is better than gmail for mail.

it allows free email aliases, much less ads and tracking.

I presume the normal "web mails" (like outlook.com, gmail.com etc.) work fine with email clients like Thunderbird Mail and such.

I have more than one email account in hotmail.com/live.com/outlook.com (for historical reasons), and I can have them all in Thunderbird, ie. I just run Thunderbird and I have instantly access to all the different email accounts. At the same time, I am also able to read the emails with web browsers, in case I need to access email from some other PC where I don't have Thunderbird set up.