Unfortunately, forums with decent security, forums that are free, and forums that have the features you are looking for are groups that rarely overlap.

SMF was the only viable option for a forum I started. My requirements were

    1. An events calendar
    2. Discussion boards with varying permissions
    3. Tiered membership 
    4. Automatic events newletter
    5. Costs less than $10/month to host
    6. Takes less than 2 hours/month of technical work to run
    7. Can be set up and running in less than 40 hours.
    8. Can be run/hosted by someone else if I'm no longer have time to manage the site.

I'd write my own but there's only so much time available in a day. I'll be looking into a way to add bcrypt hashing to SMF as a plugin. Not an easy thing to solve.

Edit: "newsletter" isn't the same thing as forum reply notifications.

Edit2: Added requirement #8.