I am part of a 501c3/c4 organization that needs to use a robust collaboration platform.

Our staff of 6 uses Slack Pro and just pays the monthly cost.

We have around 100+ volunteers currently marooned on Facebook and other digital spaces. We have a free slack set up that is pretty active. But we are up against the limits of the free plan like 90 day cap on searching older messages.

The Slack non-profit policy excludes all advocacy organizations. Bummer. https://slack.com/help/articles/204368833-Apply-for-the-Slack-for-Nonprofits-discount

Basecamp doesn’t say they exclude such entities. Still, $9/month/user is unaffordable.

Any ideas for free or cheap alternatives?