Speaking of Firefox, there are some useful add-ons for Firefox to do utility things like speak web page text aloud. Then there are add-ons to stop trackers and delete cookies and take back some of your privacy. There are even some fun add-ons like LaserCat. Ken or any cat lover would like that one. You get to be in control of stopping, starting or managing these add-ons. If anyone has questions about Firefox add-ons I'll help them to the best of my ability. Thunderbird, by the same people who make Firefox, is the best email client I've found. Microsoft products are intrusive and want to report to Microsoft every thing you do, plus they are just not that well written. I do what I can to avoid using Microsoft products. The only add-on I use in Thunderbird changes the theme and colors for the Thunderbird pages. My bar across the top of Thunderbird shows two birds. Cool. There are probably other good add-ons for Thunderbird that do more useful things. I've just never looked at or tried them. They're easy to find, though..
I, too, use Thunderbird as my main email gui. Everything comes through my webmail from the ISP but is presented in Thunderbird. It provides everything I need as a personal email. I have a Gmail account now, but I never use it and am considering deleting it (if that is even possible). When I worked, we were prohibited from sending even encrypted confidential information through "unsecure" email providers. That included all web-based email. Gmail was always considered the least secure of all, as somewhere hidden in their user agreement is the provision that Google gets to keep a copy of all attachments sent on their service. What they use that info for I have no idea, but I know when it is active, all your Google accounts are funneled through the email server, e.g., YouTube, etc. I shudder when I see doctors and dentists using Gmail to communicate with patients....