You need small server and some database, lets say MySQL, so you can just follow instructions and use
jRDC. In this case you should create app that can read data from database, so you don't need to login to the server every time you need to check the new data.
I prefer Digital Ocean, but everyone have there favorites. Smallest standard droplet cost about 5 $/Month.
You may also found some free or super cheap VPS servers.
There is also possibility to create
web server and use it
send email for your own email.
You have to create some kind of verification method for clients, so everyone can't just spam new data to your server.