If you do not need help for configuration but you are sure that you have found a mistake or wrong behavior in the Evolution software, or if you want to request a feature, you can file a report in the GNOME bug tracking system. Note that this requires registration first. Please try to avoid filing duplicates and check the bug writing guidelines first.
Also note that GNOME distributions sometimes introduce their own changes in Evolution that are not included in GNOME Evolution. This is hard to recognize for users but if you are aware of it please file a bug report in the bug tracker of your GNOME distribution instead.
When reporting bugs exact information is welcome as it makes it easier for others to reproduce and fix the issue. If possible please include information such as the Evolution version (under