I'm trying to find an internal messaging solution for a medium-sized nonprofit organization. I would arrange domain and hosting, just need a setup whereby people can register to get into the system, then opt into any of a dozen or so subgroups. Each subgroup would have its own unique email address, when a user sends an email to the address, it then sends an email notification to all. Need capacity for about 200-250 users total. Can this be done by just using a blogging platform like Wordpress, creating the "subgroups" as categories and then setting up feeds for each category to handle delivery? Or is there a better solution?
I think you should use a forum or more powerful CMS system. Like VBB or drupal/Joomla, wp is weak in CMS area.