Some people even use Raspberry Pis as their NAS. I use an old MacBook (5th gen i5) as a home server with 2 external hard drives as a NAS, which also runs a few docker containers like Jellyfin. Before that, I was using an old PC with 1st gen i3 for all these things.
I moved from Gmail to ProtonMail, then to Mailbox.org. Ypu can set up a mailserver on your home server, but you would need a VPS that would forward the traffic to and from your home server without you needing to open any ports. This guide can help you with TLS passthrough.
But setting up your own mailserver is a big hassle. Just pay a trusted provider and keep your inbox, and preferably all emails, encrypted with GPG.
I have been paying for Proton Unlimited for a very long time. About a year ago, they changed their prices for new users. currently it is $12/m, but I have to pay only $7.50/m, and yes, I pay monthly.
I use Proton Mail with 3 custom domains, and I am an always-on VPN user. The VPN connection is always great with good speeds, but sometimes bad pings, but have a bad Linux app (yes, the new one as well). I also use their drive, currently using ~200GB. I have never touched Proton Pass because I have a self-hosted Vaultwarden server.
But I am seriously considering discontinuing their service, specifically due to their poor Linux support. Their VPN app is shit, they don’t provide and not even developing a Linux app for Drive. But their are 2 reasons that make me continue their service. One, I do not really wish to self-host my email, and I do not want to use Tutanota, because I need Thunderbird. Two, there are no trusted VPN providers that give Indian IPs.
I was paying $7/m for their mail, VPN and drive services. One of my major reasons to switch was their lack of linux support. They claim that it is hard to find Linux developers. Second reason was their drive’s download and upload speeds were terrible, from where I am sitting. Their VPN service is great. I always got great speeds, but their linux apps have always been terrible. Their mail service is also great, but I would like more control over it, like Mailbox.org. on Mailbox, I can encrypt my inbox using a different key, while also having the SMTP submission feature. I really ned that to integrate emails with my websites and services. Mailbox can also encrypt their cloud drive with our key, while also providing WebDAV support (how cool is that). Their mail app on android is open-source but is not available on f-droid. And the apk they provide on their website neither has a notification functionality, nor does it auto-update. Another reason was that I was limited to 3 custom domains, unless I buy their business plan. Mailbox has no such limit.
One final reason was that I did not want to keep all my apples in one basket. So, for mail, I am using mailbox, for storage, I am using a personal nextcloud and a Hetzner managed nextcloud, for VPN, I started using mullvad, but their speeds are terrible and connections are unreliable. For passwords I am using self-hosted vaultwarden.
There are a few more reasons that I do not remember, now. Proton is great, I still trust them. But these small things really go a long way.