It’s doubtful that a /e/ Cloud will work @home : residential IP addresses (and furthermore dynamic DNS) are unlikely to work for emails.
That’s why it isn’t documented.
You can find decent DNS & Docker-compatible VPS hosting for the price of a good beer, monthly.
For example @Hetzner :
Edit, this is off-topic, but … I have a regular LAMP setup on a first edition Rpi. It runs ok, reassuringly slowly. It is possible that Nextcloud would be too big for my 512M!
Found a tutorial on how to build a RasPi 4 home server on “Magpi.cc” , Issue 108. I guess it’s open access, but you can donate or pay for that magazine.
I want to go with this build as soon the RasPi 4 8gb is back in stores, it’s completely out of stock.
Would be nice, if ARM devices could get some love from /e/.