I try to keep personal and professional accounts separate on my computer. For example I typically use Safari for work related things and Vivaldi for personal stuff. I know that Safari supports profiles that would accomplish the same thing, but using entirely different browsers makes it easier to keep things straight. Similarly to web browsers, I split up my email by application. I used the macOS mail application for professional email, and accessed my personal email via a web browser (i.e. Vivaldi).
Recently, I decided to try out Thunderbird and bring all my email into one application. It can handle multiple accounts and does it with pretty good separation. Also, I wanted to set up PGP for my email, and Thunderbird seemed like the easiest and best way to do it. Almost no one uses PGP with their email, but that doesn't mean I can't. PGP can send fully encrypted emails, but this only works when the recipient has PGP set up, too. Since most people have not set up PGP, instead I send emails with plain text content and a digital signature file attached. This means that PGP uses my private key to generate a cryptographically signed bit of text that, when combined with my public key, can prove (or disprove) I sent the message. It can also be used to confirm (or deny) that the content of the email wasn't changed between sending and delivery. Almost nothing I send is super important, but the effort involved was small, so why not? I've pasted my personal email public key on my About Me page if you want to use it.
Because Thunderbird is open source and is heavily based on Firefox, you can add extensions to it, just like Firefox. I decided I wanted an extension that adds random quotes to the bottom of my new messages. Some quick searching showed this didn't exist, so I decided to write one. And by "write one," I mean I asked an AI to write one for me. I don't know JavaScript, I don't know how to write Firefox extensions, and I didn't want to learn. The AI did a good enough job and only had one bug that needed fixing (which it fixed after being asked to). I've published the code on github, and it is simple enough to use if you're interested. The plugin has a few built-in quotes, and I have made a library of cycling quotes that will be added to my emails going forward.
Finally, I can endorse Choosy. This is a simple utility that allows you to choose which browser opens up a link. For example, I have it set to send all web links I get in Slack (which I use for work) to Safari. If there is no predefined behavior, it gives you the option to pick which browser to send the link to. It's $10, so it's not free, but if you're like me and want this kind of separation, it's worth it.