Comment 2 for bug 261093

clamav-base.postinst executes newaliases if available. As exim was unpacked already at this time, newaliases was found and executed. But exim was not yet configured, therefore user Debian-exim wasn't yet in /etc/passwd, and that's what newaliases complains about.

I'm not sure which packet could handle this correctly. Despite of the error message "exim: failed to find uid ...", there's probably no harm here - maybe it could be a valid solution to just redirect newaliases' error message to /dev/null in clamav-base.postinst?