We need a mailing list package similar to Python Mailman. I'd use Mailman except for one thing: we want to link the subscriber list to a table in our MySQL database. We want people to be able to opt in/out and control delivery options directly from our site in addition to via the email interface. I don't think Mailman has an easy way to link to an MySQL table.
There is a MySQL member adapter in
https://sourceforge.net/tracker/?func=detail&atid=300103&aid=839386&group_id=103
I haven't tried it, and from the readme, it seems you'll need some Python expertise to use it, however, there are also comments in the tracker by other people who have successfully used it.