Thunderbird needs no presentation indeed but only a quick review on its recent improvements. One of the least complicated e-mail client to be created, this app gives you access to all its features as soon as you have typed in the user name, the e-mail address and the password. You get to create a personalized address for free, check multiple e-mail accounts in the same time into a tabbed interface and add as many people to you address book as you need.
One interesting function reminds users to upload the attachment before hitting send. Other options include multiple-channel chat, whether on Facebook, Google Talk, IRC, Twitter or XMPP, web search and an archive.
Furthermore, large attachments related problems and tracking issues will become a thing of the past. The latest improvements include phishing protection, great when a received link sends you to a different place than originally believed.