HoustonBOFHB
The problem with selfhosting email, is that unlike other self hosted things, it lives in a distributed system. It has to talk with other mail servers and they have to talk back. The second part is hard due to spam measures…
For just the software side, you have a few options. Mail cow, iRedmail, and Mailinabox are very popular. Linuxbabe has instruction on how to build it from scratch using postfix. (Good to learn, but a LOT of work) But recently I stumbled on Modoboa. It does not need docker, so you can run it alone. It is not split foss with everything good behind a paywall. And it does not install unneeded apps like DNS for no reason. But keep in mind that I have only evaluated it so far and not yet put it in production.
Now for the other needs… To receive mail, you will need a static IP. Theoretically, you can get by with a dynamic DNS, but it will not go well. Your IP will change, and it will still be cached and you will lose email.
To send mail… (This is a lot more) You will need a clean static IP, with a fqdn and ptr record matching. It will need to be clean, and not in a blocked range of IPs. You will also need SPF and DKIM records, and may need dmarc. And you will need to warm up the mail server and maintain it’s cleanliness. Or you can contract out your outbound to other companies like MXroute. If you farm out your outbound, it eliminates most of the complaints above. If you have the skill, you may be able to only route Microsoft and Google destined email, and direct deliver the rest yourself. (I am working on this)
More spindles means better performance. But also more power use. Only you can decide which is more important.
A lot of this will depend on who is going to maintain this. Because there is cheap, fast and easy, but you can only pick two… I will tell you that what you have no is the cheapest crap they think they can get away with. The best way to do this is with a cable modem alone, a solid router with no WiFi, and WiFi access points wired throughout your house. But this is also more complex to manage. The easy way is an Orbi like system where you get an ecosystem based on mesh networking. This will slow you down, add latency, and can be a bear to troubleshoot when something goes wrong.
But the question is what are you willing and able to do?
https://www.ebay.com/itm/254845248977
Cisco Catalyst 2960-X WS-C2960X-48FPD-L 48 Port GigE PoE 2x 10G SFP+ Switch
2 SFP+ ports, and 48 1gig Poe+ ports. A solid switch that has a lot of help and documentation on the web. Also, learning Cisco will not hurt your job options.
Edit: Note that this is cheaply stackable if you need more ports. Yes, that will be a bit power hungry.
A wireless cammera will be more trouble than a wired one, and it will be more trouble than you think. That said, if it supports rtsp, there is a lot of DVR software that will work with it. Blue Iris was mentioned. ISpyConnect also is solid. I use Zoneminder.
You have to understand the priorities of the rack server market.
#1 is dependability. It needs to keep running no matter what. Evenrthing is built around overbuilding it. More cooling, dual CPUs, Dual power supplies, lots of drives in RAID…
#2 is size. Colo space is expensive! So keep it small. So everything is densely packed, which is bad for airflow. And you get stacked small fans running at the speed of sound.
#3 is performance. Yeah, you would think it was first, but it ain’t. But that means 10k and 12k spinning drives. These are loud and noisy!
Way down the list is power… When you consider the cost of the hardware new, the cost of the colo space, and the cost of the people maintaining it, the power cost is next to nothing. The only thing less important than power consumption is sound which is not even on the list…
Now, compare that with workstations. They have a lot of the same components like Xenon CPUs, lots of ram, raid… But they sit on a desk, so noise, heat and power are a real concern. And they are often overlooked in the used and refurb market. So for less money, you get server like components and performance, in a quieter and more power friendly form factor.
I am running Zoneminder. I have played with Frigate and it is not really production ready. And Zoneminder, while not fancy, works every time and has some of the best still pictures of anything out there. I will keep looking at the next new thing, but I am not shutting off Zoneminder until something is solidly batter.