Mutt is described as 'small but very powerful text-based mail client for Unix operating systems' and is a popular Email Client in the office & productivity category. There are more than 50 alternatives to Mutt for a variety of platforms, including Windows, Linux, Mac, BSD and iPad. The best alternative is Thunderbird, which is both free and Open Source. Other great apps like Mutt are Microsoft Office Outlook, Mailbird, Evolution and eM Client.
Historically, Icedove was a re-branding of Thunderbird by the Debian project, with minimal modifications, in order to resolve branding disputes. Debian since discontinued Iceweasel in February of 2017 after reaching an agreement with Mozilla over the use of it's trademark.
Eudora started in 1988, at the University of Illinois because the internet was a growing and burgeoning place, but email was not really established on the desktop computers that people were using at the time.