This howto is about getting rid of Incredimail e-mail client without data (email) loss.

First be aware that Incredimail is a closed source money-oriented program. The last thing Incredimail developers would like you to have is freedom to choose. That’s why you are not given any chance to export your emails to other clients! This would have never happened with an open source software.
Incredimail developers only provide you with two choices:
1) pay and switch to the commercial version
2) pay and buy a backup tool that enables you to export your emails.
In either cases PAY.

By the way, in order to switch to Thunderbird you have to do these steps:

1. Download Incredimail Backup Pro from these links and install it using the registration data provided

   http://www.zshare.net/download/56485418ff73ba4a/

   http://www.filefactory.com/file/af30547/n/IncrediMail_Backup_Pro_v2_6_zip

2. Choose Extract to EML and select your profile. Save the transcoded contents of your profile into a newly created folder.
3. I guess you have already downloaded Mozilla Thunderbird, just in case visit: http://www.mozilla-europe.org/en/products/thunderbird/
4. Download Thunderbird ImportExport Tools from this website
   http://www.nic-nac-project.de/~kaosmos/mboximport-en.html (download link is at the bottom of the page)
5. In Thunderbird open menu Tools -> Addons and drag & drop the downloaded file over there, restart Thunderbird when requested.
6. In Thunderbird open menu Tools ImportExport and choose Import from EML with subfolders. Select the folder you had created and seved your exported data into.
7. Remember to remove Incredimail and Enjoy!!