What are some alternatives?
When comparing PopTrayU and Shift, you can also consider the following products
POP Peeper - POP Peeper is an email notifier that runs in your Windows task bar and alerts you when you have new...
Station - Station unifies all your work tools in one neat & productive interface.
nPOPuk - nPOPuk is an ultra-small, but comprehensive, e-mail client that runs on a wide range of...
Thunderbird - Thunderbird is a free email application that's easy to set up and customize - and it's loaded with great features!
Mia for Gmail - A desktop email client for your Mac, without a browser !
Mailbird - Mailbird is the best email client for Windows 7, 8 and 10