My parents are getting a new tv, and are asking for recommendation. I think all I can influence is the brand/model (not realistic to propose rpi and more complex systems). I instinctively avoid google/android and lean towards anything else open source, so probably LG WebOS.. But I had bad luck searching for more detailed comparisons. Maybe you have experience or opinions?
I am using eMclient for several years now. I would have loved to use open source, but experience of using Thunderbird was unbearably sluggish and glitchy. Other options for windows were simply lacking. EM is far from perfect too, but still better. I hope to retry Thunderbird in upcoming years to check if things under the hood changed much.