Although I am somewhat concerned about privacy, my main concern is security. I don't want to be tracked by google ad text as I am when I use my current gmail. And, I feel like that renders me vulnerable not only to ads, pop ups, videos but also outright spamware, bugs, etc. I recently suffered a related attack. And, I want to reduce my risk along those lines.
Use gmail. If the ads are unacceptable, use an ad-blocker, or a imap client such as Thunderbird.
When it comes to security, few can beat google. They have huge resources, and they can infer connections between happenings tat someone with a smaller service can't. They offer the advanced protection programme, which makes phishing attacks next to impossible, and standard password recovery attacks very much more difficult.
They monitor your habits, and blocks logins from unknown location. They alert you on the phone if they see a new login. And so on and so on.
From a security perspective, this is good. It makes it hard for an attacker to gain access, even more so without your knowledge.
So my suggestion? Stay with gmail if security is your focus. Consider using a mail client such as Thunderbird if the ads in the interface bugs you. If you want encryption, there's many possibilities, including browser extensions if you prefer to use the web-mail interface.
Regarding popups, I have never seen an popup in gmail that was unsolicited. I've never seen spamware or videoes either. I've found bugs, but all software has bugs. And google tends to be pretty good at patching bugs, especially if they affect security.