I want to have an ability to easily making new accounts by duplicating them with all the settings. Now all the clients I tried, they have only from-scratch creation process.
You may assume that my requirement somehow corresponds to identities/aliases feature, and you are right. I want to handle multiple identities without a hassle.
I checked this, this and this question but didn't find a good match, all the answerers advise Thunderbird, and I don't like the Thunderbird. It is slow, cumbersome, non-efficient and I dislike its UI.
Maybe there exists an email-client with duplication feature? GUI is preferable.