- Public Channel Messsages: workspace default (14 days), user-configurable.
- Private Channel Messages: user-configurable.
- Direct Messages: user-configurable.
- Message Quotas: None, talk all you want!
To configure message retention while in a DM conversation, private, or public channel:
- Click on the gear icon and select "Set message retention policy..."
- Set retention type and, if desired, duration.
- Files: never expire.
- Maximum File Size: 1GB
- Storage Limit Per Team Member: 1TB (that is across all workspaces/channels).
- Files shared via Dropbox, OneDrive Google Drive and Box integrations do not contribute to the storage limit.
If you need more space, consider deleting older files you're no longer actively using in Slack. You can find a list of all your files by filtering on files from "Just You" at your-workspace.slack.com/files
To share larger files or archive older files outside of Slack, explore Data Storage and Collaboration Options.