Neomutt (with notmuch) is not easy when starting from scratch. Luckily there are some configurations online that get you up and running quickly. It still requires some efforts to get use to it and configured to your detailed and specific needs. I put sweat to build mine but it worth every single drop.
That being said that's what makes its strength. It's not an email client, it's your email client. Once it's configured, it's good forever and using anything else feels like a pain.