The mailing list provides a way to have threaded conversations about particular topics. Unlike the wiki, it provides a way to actively "ping" the community. Everyone is welcome to join the mailing list and no matter where you join us, you will reach our community!
Element is the default client for accessing Matrix and provides desktop, mobile, and web apps.
Occasionally the Element desktop app can get stuck trying to send or receive a message. We've found that if you run into these kinds of issues, opening Settings, selecting "Help & About", and clicking the button that says "Clear cache and reload" under the "Advanced" section may resolve the problem.