Buy European

You can use tools like Stallwart and Mailcow qnd even Mail-in-a-box to make mail hosting a LOT easier. One does not simply configure ClamAV as a milter and chaining DKIM validation too late I the process is a great recipe for random spam status issues.

You just have to accept that nobody using Google's or Microsoft's email servers will receive your email in their inbox ever again. All of your outgoing email will be marked as spam, unless you slowly trickle non-spam emails at rates of dozens to hundreds a day to various email servers to build up IP + domain reputation. If you're not a marketing company, that will probably not happen. That includes almost every company, big or small, local or international, using their own domain names. Customer service will likely ignore you and email that doesn't get delivered will be considered your fault. Of course you can fight against the system by still using an independent email server (like I do) but know that you're a tiny drop in an ocean of The Big Three email servers.

Also, reserve four to eight hours a month for maintenance and dealing with problems. Easy to do as a student, challenging as a parent.

Futhermore, for your domain name, make sure to check the requirements. You may lose the rights to your domain when you emigrate, or when your country ceases to exist (unlikely) or leaves the economic union controlling the domain (like the British people with .eu domains). You may find the Taliban in control of your domain one day (because you chose the funny .af ccTLD). Also pick a TLD that's not full of spam already, like .biz or the ones that used to be free (.tk).