That is pretty much why we don't have a chat system right now, to be honest!
The question's been raised many times in various threads, but to recap there are several issues with in-game chat system that we aren't ready to face yet; the key ones being:
It is indeed a significant development requiring lots of sub-features. As you've correctly pointed out, ability to manage contacts, mute/block/ignore, create channels and groups will be required; no one's really going to be satisfied with a non-configurable message box and a free-text input.
And as it's only me developing the game right now this functionality is just a bit too time-consuming compared to some other features that are being requested more frequently.
Moderation: you may know that I've built another game published by Epic Dragon (a browser-based MMORPG named "Flamefrost" - flamefrost.com) and that game does have a fully-featured chat box.
Of course, an MMORPG cannot function without an in-game chat & mail, but occasionally I do wonder if it actually causes more harm than good. The number of times our new players have been discouraged from playing by spammers or malicious players (i.e. haters or fans of our competitors ) is greater than I can remember.
Additionally, having an in-game chat does involve certain legal responsibilities, e.g. if our in-game chat becomes a hub for arranging criminal activities we may become liable for any real-world issues arising as a result.
So no chat can be left unsupervised and we just don't have enough people in the team to monitor a chat in DE (I'd love to do it myself, but then we'll unlikely see any development done; real-time chat moderation is a full-time job ).
That is why our chat is currently based within Discord, a server run by our veteran players (and they have full control over it). This approach is really helpful and time-saving for me!
A very interesting feature has been suggested in the past, which involves "message-less" communication between players: i.e. the ability to send pre-defined messages, commands or requests (e.g. suggestion to attack someone, meet in Discord etc.).
This way it would be impossible to send any offending content and no moderation or excessive development will be required.
I quite like this idea myself, but I haven't been able to finalize the details of its implementation yet, so I'm not sure when it will appear in the game.
However, as always, I'm open to any alternative ideas or suggestions.