Sadly, there aren’t many email clients. Seems like it’s either outlook or thunderbird for windows users. There are a couple others for Linux users. I run Kubuntu and use Evolution which is similar to thunderbird. Has Contacts, Tasks, Calendar, Email. No version for windows though.
Claws isn’t too bad. Eudora is an oldie but good iirc.
https://en.wikipedia.org/wiki/List_of_email_clients#Operating_system_support
Thank you for the information. I am really old-school. I use a planner for contacts, tasks, and calendar. I just want a simple and safe e-mail server.