Thanks for all the suggestions, I've tried apt-get install resulting in: ivan(a)silver:~$ sudo apt-get install Reading package lists... Done Building dependency tree... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. My understanging of the above is that my system is clean. (FYI: I'm running Ubuntu 5.04) I have installed exim4, exim4-config, exim4-doc and found that anacron, at, lsb, mailx & mutt were still installed, but postfix, postfix-lts, ubuntu-base had been removed (as expected). So all seems fine. Thanks for all the feedback - it looks like it was just a storm in a teacup. Ivan. Matt Brown wrote:

What version of Ubuntu are you running Ivan? Do you know if the package system was clean before you tried to install Exim?

My suggestion on how to fix this would be to drop to the command line, run apt-get install (no arguments). This will handle any packages that are not in a clean state. Once you can run apt-get install (no arguments) and have it return without doing anything, then try apt-get install exim4 exim4-config (or use synaptic if you prefer).