Slack keeps your entire company conversation, prices it per person, and hides your own history behind a message limit until you pay. Mattermost gives you the same workflow on a server you own, where the archive is yours and the cost does not scale with headcount.
What you get
- Channels, threads, voice and video, plus file sharing and integrations
- No per-seat pricing. Team Edition is free, however many people you add
- Your archive stays yours, with no vendor retention policy over it
- PostgreSQL bundled, nothing extra to deploy
Get it running
Give it real resources
Mattermost is one of the heavier catalog apps: around 2 GB of memory, two cores and 10 GB of disk to start. Pick an offshore VPS accordingly, and remember uploaded files grow the disk over time.
Install it in one click
Install Mattermost from the catalog with the hostname you intend to keep. It becomes the site URL used in invite links and OAuth redirects. See how one-click installs work.
Create the first account and the team
Open the site and set up the first administrator account and your team straight away, before sharing the address.
Invite people and lock down joining
Send invites, then restrict who can create accounts so the server does not accept strangers. Decide early whether email domains are restricted.
A fresh instance with no administrator is claimable by whoever reaches it first, and the first account is the one with control. Complete the setup immediately after install, then invite people.
Team chat accumulates credentials pasted in a hurry, contracts, personal conversations and everything a departing employee said. Keep it patched, restrict who can reach it, back it up and test the restore. Consider a retention policy so the archive does not grow into a liability you never intended to keep.
The site URL you install with is embedded in invites and integrations. Changing it later breaks outstanding invites and OAuth redirects, so choose the domain before you roll it out.
Mattermost is a Slack replacement for one organisation, with a familiar interface. Matrix Synapse is federated with end-to-end encryption, which suits talking across organisations or when encryption matters more than polish.
Start now
Spin up an offshore VPS and install Mattermost from the catalog, or read the documentation.