Comment by QuantumGuy

As I said earlier in a related post "email clients are stuck in the 90s. The way they look and organized hasn't changed in 20 years. You need to throw out all you think an email client should be and make your own. That is my sincerest suggestion. If you do not believe me go look for yourself. Outlook,Yahoo Mail,Gmail,etc all look the same as the did 20 years ago. I use Thunderbird but I hate how it looks and works." Plus it is still insecure but Mozilla may fix that with Persona.