Is it secure to use HexChat?
I have read that irc servers are not very secure and anonymity can be breached for those who are connecting from tor network. Is there any truth in that?
Is it secure to use tutanota client?
If i use tor browser to create tutanota email account can i download and use their client for linux? Can this compromise my anonymity?
Is there other secure private messaging programs i could use on whonix?
For example, can i download and use pidgin and stay anonymous while chatting?
What guides i should follow if i want to stay anonymous when communicating with other people from Whonix?
Recommended reading: /wiki/Chat
In general, the most secure scenario is when you only use Tor Browser on top of Workstation.
Whonix is created by design all apps are going through Tor but other apps can collect metadata to create a unique fingerprint so anonymity can be reduced to pseudonimity. But in general, it is hard to gain full anonymity. If you don’t have an alternative, then you can use any app you want with Whonix. But Tor Browser is still preferred for most kind of activities
Using XMPP + GPG on top of Tor is the most secure type of chatting I think. But if you’d like to use not only private messages but group chats then you can use OMEMO encryption. Note that group chats are stored on XMPP servers.