setting up groups in sendmail
I'm trying to find a simple way to setup mail groups in sendmail. I need to set up a total of about 40 groups, each group will contain anywhere from 5 to 60 users so using the aliases file would be very time consuming, and I'd like to avoid it if possible. If I could I'd like to be able to use the user groups so I can have a primary and secondary group for each user, so the primary group can be all the users in a building and the secondary group can be a certain department in the building.
Can someone tell me the simplest way to do this? I've seen a lot of people suggest using postfix instead of sendmail. If postfix will do this how hard is it to switch from sendmail to postfix?