My school has provided us some emails with a custom domain (not @gmail.com but @myschool.smth) and we as students are only able to login via gmail, however i obviously do not want that. What can i do to prevent that? I tried logging into the email via Thunderbird but i get blocked because my administrator doesn’t allow that.


You need to suck it up; work and school choose their email providers. Use it purely for work - not your personal life and not for anything private. Use it in it’s own browser container or even it’s own browser if you want. Especially if your college doesn’t provide POP3 or IMAP access. It is worth contacting the college IT to see if that is something you can use though - it my be something they can enable even if it’s off currently or provide instructions for the correct server addresses. It’d be surprised if they didn’t have either but they may want it all locked down in gmails services. More fool them.
My work (like many) uses Office 365 including Outlook for mail. So I have the crappy MS Office apps on my phone. But it is used purely for work (and I mute all notifications).
I use Firefox and have google account for my android stuff, which is in a container. And I also use the linux version of Edge (which is a flatpak) for the rare time I want to look at my work email of office online on my PC.
Why are you using edge for email? I use Firefox in Linux. In a container, of course 🤣