I like that this is open source software, meaning anyone can use it for free. It's easy to install and configure, you just need some basic technical skills. The documentation could be more in-depth (I'm still learning about all of its features), but overall I think it has been helpful so far. There are many other options out there if you're looking at something similar. This one offers much better security than others because it uses HTTPS by default. With other providers, your messages aren't encrypted until they get sent through their servers which means someone with access to those servers could read them easily.