Kopete is a flexible and extensible KDE graphical client for instant messaging in real time (IM client). Kopete is a modular IM client, all supported protocols are implemented as plugins activated without any reconfiguration of the main application. In the basic delivery of the app developers include a small set of plugins and additionally a number of templates for developing modules adds support for the new protocols.
Kopete is part of KDE desktop environment, the application interface is very simple and highly customizable (which is traditional for most KDE apps), supports the installation of various styles, emoticon sets, and more. The basic capabilities of an XMPP client library based on Iris (a powerful and simple library for working with the XMPP/Jabber). In addition to XMPP/Jabber (like Google Talk) Kopete has support for protocols MSN Messenger, AIM, Gadu-Gadu, Novell GroupWise, ICQ, Meanwhile, SMS, Yahoo, Winpopup, IRC and Skype (using the official client), supported SSL/TLS and OTR encryption (activation of the corresponding module). Kopete allows you to add/remove/merge a lot of different contacts (buddies) from different protocols into a single MetaContact, it is possible to simultaneously connect to multiple accounts (accountan), realizes the connection to the chat (simultaneous communication with several people), you can set the status (both automatically and manual) and more... Installation into Linux Mint: On the screenshots below, I have not installed Kopete in KDE. I use Cinnamon. So when you install a loaded a lot of extra KDE packages. Keep this in mind.
sudo apt install kopete
May the Force be with you, Good Luck!!! https://userbase.kde.org/Kopete