Apple Mail
Microsoft Outlook
Thunderbird
eM Client
Mailbird
Gmail
Postbox
ProtonMail
MSD Organizer
C-Organizer
Info Select
AllMyNotes Organizer
Efficcess
My Ultimate Organizer
Zoho Notebook
Trilium Notes
Apple Mail MSD OrganizerMicrosoft Outlook - Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.
C-Organizer - C-Organizer is a robust software tool designed for the professional manager that permits them to organize business activities altogether.
Thunderbird - Thunderbird is a free email application that's easy to set up and customize - and it's loaded with great features!
Info Select - Info Select is a Personal Information Manager that organizes Internet data, notes, to-do's...
eM Client - eM Client is a fully-featured email client for Windows and macOS with a clean and easy-to-use interface. eM Client also offers features for calendars, tasks, contacts, notes, and chat.
AllMyNotes Organizer - AllMyNotes Organizer is a multi-functional hierarchical information manager for Windows.