Using Update Manager after removal of Evolution

I could not get Evolution to work properly so I removed it by typing 'sudo apt-get remove evolution' in a terminal window and replaced it with Thunderbird. Since then, every time I run update Manger it produces a list of things for updating Evolution. I remove the ticks from all these packages/files so that they are not downloaded and installed but I have not been using Ubuntu (Version 8.04) for long enough to know whether I get notified about these files for download because there are still references to Evolution because it is not completely uninstalled, on my system or because they are needed for some other functions. If these files are not needed for other, non-Evolution, software is there any way that I can stop being notified about them? It is getting tedious to have to go through the list of software to be downloaded and un-mark those relating to Evolution. On the other hand, if they are needed for something else, could someone please tell me what they are needed for?