nPOPuk

nPOPuk is an email client that comes with support for local data saving options, settings for message replies, connection/disconnection parameters, audio and visual notifications, sorting mode for emails, and password-protected access to the main window. The utility is portable and can be kept on pen drives or other portable devices.

Simple GUI

The layout is extremely simple but also colorful enough to look good. All icons reflecting the major program's features are visible right from the primary window of the application.
Users have to connect to a specific email server by introducing their email address and password, and nPOPuk immediately accomplishes the process. This way, it acts as an email client for all those that plan to keep data on a flash drive instead of logging into another person's computer.

Built for mobility

Since nPOPuk supports POP3 and SMTP accounts, users can enter their account details right during the pop-up window prompt that asks for such details.
Users can write a new email right from the 'File' menu. The great part is that it can also control multiple email accounts. In case you plan to keep track of multiple accounts, you can introduce all of them and then have nPOP check and update them with just a single push of a button.
Global options are rich in filters, as well as sending and receiving options. Additionally, users can very easily implement their own signature messages from the 'Reply' settings tab.
The application is lightweight so it doesn’t put a strain on any computer it works on, and since the interface only emulates the accounts it's connected on, there won't be any other extra task managing features running in the background.

Conclusion

nPOPuk is a highly advanced email client that helps users synchronize multiple accounts on the fly. If you're a person who travels a lot and isn't glued to a computer/smartphone screen, this may be the perfect solution.