Pop Peeper is a freeware email client and notifier that can be run portably from a USB device. This portable Email Software can automatically import your current email accounts from Outlook Express or Windows Mail and can also be used with your GMail, Hotmail, LiveMail, MSN, Yahoo, GMail, Mail, MyWay, Excite, iWon, Lycos, RediffMail, Juno and NetZero accounts.
Sylpheed is a clean, powerful and easy to use email client that can be run portably from a USB flash drive or other portable device. Built mainly for Unix like systems such as Linux, BSD and Mac OS, there is also a version for Windows users which is our main focus in this review.
Reach-a-Mail is another portable email client that enables users to bring their POP mail accounts with them wherever they go on a portable USB device or flash drive. Like most email software, It features an address book to store your contacts and supports SSL and TLS.
Thunderbird Portable is a free open source portable email software that allows you to take all of your saved email and contacts with you wherever you go. It can be run from a USB flash drive or any other external removable device.