My university has the listserv software in place and we run most of our bulk mailings through that. I found it quite easy to use once I learned how to use it. After a reorganization someone else was given that part of my job and couldn't be bothered to learn how to use it. She switched to the for-fee "EMMA" software and a friend who has to use that now says it's a pain in the ass, at least for formatting. I don't notice it changing the URLs in links or mail.