What’s the most secure messaging platform for enterprise use?

I have been researching enterprise messaging platforms for a project and noticed that every solution seems to highlight security as a key feature, but the actual approach varies a lot.

Some platforms focus on end-to-end encryption, while others highlight private cloud deployment, on-premise hosting, compliance certifications, admin controls, or complete ownership of messaging data.

I came across solutions like Microsoft Teams, Mattermost, Rocket.Chat, and MirrorFly while comparing options. MirrorFly caught my attention because it seems to focus more on customizable, enterprise-grade messaging infrastructure rather than just a ready-made chat app.

which have actually evaluated or deployed enterprise messaging platforms?

• Which platform do you consider the most secure and why?
• How important is self-hosting or data ownership for your organization?
• Are encryption features enough, or do compliance, access controls, and deployment options matter more?
• Has anyone used MirrorFly or similar platforms in a production environment?

Would love to hear practical experiences rather than just feature comparisons.

I need a genuine forum question because it shows the person has already explored the space and is asking for real-world feedback instead of simply asking “what is the best platform?”