As a system administrator, you must be receiving your important server notifications by emails. Email has been used since decades, but it is slowly replaced in everydays life by social networks. With social network clients, messages are usually displayed as thread and get instant notification on your smartphone.
So, why not receiving your main server notifications on one of your favorite social network client ?
Telegram is becoming a very popular social network as it is free and multi-platforms. It has also a unique feature : it's allowing the use of bots. Bots are very interesting as they can be seen as an application account associated to a real person's account. They are able to send or receive messages to/from either an individual account or a group.
So, instead of sending a mail, it could be very interesting for your Debian/Ubuntu server to be able to send you Telegram notification. You can for example create an administrator group and send all your server notifications to this group. Any administrator belonging to this Telegram group will get instant notification from the server.
This article explains how to setup a server environment to very easily send Telegram notifications from any of your server script or service. It also provides a script that allows you to send Telegram messages including text, photos, documents, logs, …
It has been tested on a Debian 8.5 server but it should work on any modern Linux distribution.