If you find yourself needing more CPU horsepower, try the 5. If you don't, stick with the 4.
bityard
joined 11 months ago
I self host my own mail, SMTP in and out. But I've also had this vps in the US from a small local hosting provider for a decade. Unfortunately vps providers can be a crap shoot if you're looking for a new one. My back up plan is this one goes south is to just use a cloud provider's SMTP relay service (eg aws) because their prices for that sort of thing are extremely reasonable for small volume.
Some people play with VMs for fun, or as a leaning experience. I don't think it's very productive or useful to tell them they're doing it wrong.