Upgrade Notes : Evolution 2.5 is the unstable series of 2.6 development.
New this release :
Memos component (Nathan Owens) and plenty of bug fixes.
If you have problems with 2.5.1, please take the time to submit the bug using Bug Buddy or at http://bugzilla.gnome.org. Try to fill in as much detail as you can regarding the circumstances that lead to the problem.
If you have a feature request, you can also file that at http://bugzilla.gnome.org/ don't be discouraged if you don't hear from us right away, we get hundreds of feature requests a year.
You can also check if your bug has been reported before by using the search functionality of Bugzilla.