A good email Client and also easy and most layout configurable?

[FoxAdriano]

Hello,
I have always used Eudora Pro because it was simple and the best when it came to layout configuration.
Now Eudora can no longer work and unfortunately I have to switch to another email client.
Can you recommend a good email client, simple but also well configurable from a layout point of view?
Thank you

 

[voyagerfan99]

Have you looked at Thunderbird?

 

[FoxAdriano]

No, I don't know any client because I used Eudora only. I thank you for your suggestion. I was used to seeing the IN and OUT boxes on a single screen. Is it possible to do this with Thunderbird?