exim-common is a package with common parts of exim distributions (configs,init-scripts,some common utils).
	    It is a base part of exim in ALTLinux.
exim - is a virtual package with exim-common and exim-light dependencies.

This package built with support  different lookups methods:
exim-light - minimalistic package with perl support
exim-mysql - has support MySQL lookups + exim-light
exim-pgsql - has support PgSQL lookups + exim-light
exim-ldap  - has support OpenLDAP lookups + exim-light
exim-heavy - has all of those lookups

exim-*-doc - packages with docs (html, pdf, postscript, info formats)
exim-utils - some utils for exim maintenance

Default exim configuration uses textual file of aliases in /etc/exim/aliases.
DBM file aliases.db is built from it by /usr/bin/exim_aliases.