Evolution is a mail manager that, in addition to appearance, also looks a lot like almighty Outlook (one of the tools included in the Microsoft Office office suite) in terms of functionalities. The program has a section with which manage the emails, a calendar for contacts, several calendars, a system for tracking tasks and a utility for taking notes.
Professional and totally free email manager
The tool offers exceptional performance and has some really practical features like the integrated search engine, vCard support, task lists, integration with Microsoft Exchange and Collaboration Server, synchronization with web calendars, personalized reminders and an integrated filter and security system.
It is probably the open source email manager more like Outlook, so it is optimal for the work environment, due to how easy it is to handle and the options it offers the user.