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Comparison · Comms

Maddy vs Slack

A side-by-side editorial comparison of Maddy and Slack — release velocity, themes, recent moves, and the top alternatives to consider.

Maddy vs Slack: at a glance

FeatureMaddySlack
SectorCommsComms, Collab
Velocity score0.06.3
Sparks · 30d01
Top themesmail-server, self-hosted, golang, zero-downtime-reloadmcp, developer-platform, sdk-modernization, ai-tooling
Last editorial update1h ago6h ago
WebsiteVisit →Visit →

What is Maddy?

A one-binary mail server learning to behave like production infrastructure.

maddy is an all-in-one SMTP and IMAP server written in Go, aimed at people who want a working mail host without assembling Postfix, Dovecot and a policy daemon themselves. The 0.9 line moved quickly — 0.9.0 through 0.9.5 between late March and late May — with the sequence following a recognisable shape: a feature release, an immediate patch for a broken integration, a security release, then cleanup. Configuration is directive-based, and much of the changelog concerns the behaviour of individual modules like auth.ldap, check.rspamd and check.dnsbl.

Read the full Maddy trajectory →

What is Slack?

Slack is shipping its developer platform to coding agents, not only to developers.

The developer changelog runs two tracks at once. One is a routine modernization wave across the client libraries: Bolt for JS reached v5, the Node SDK packages took coordinated major versions, and the CLI shipped twice in ten days. The other is newer and smaller in volume but larger in intent, aimed at AI tooling rather than at people writing apps by hand.

Read the full Slack trajectory →

Maddy vs Slack: editorial side-by-side

M
Maddy
COMMS
0.0

A one-binary mail server learning to behave like production infrastructure.

◆ Current state

maddy is an all-in-one SMTP and IMAP server written in Go, aimed at people who want a working mail host without assembling Postfix, Dovecot and a policy daemon themselves. The 0.9 line moved quickly — 0.9.0 through 0.9.5 between late March and late May — with the sequence following a recognisable shape: a feature release, an immediate patch for a broken integration, a security release, then cleanup. Configuration is directive-based, and much of the changelog concerns the behaviour of individual modules like auth.ldap, check.rspamd and check.dnsbl.

◆ Where it's heading

The project is systematically removing the compromises that made early versions convenient. Obsolete SASL LOGIN was disabled by default, the STARTTLS plaintext fallback was dropped, the maddyctl symlink behaviour and the implicit run command were deleted after four years of deprecation warnings, and libdns providers that have not kept up with 1.x are being cut. Running the other way is operational maturity: no-downtime config reload, queue-length metrics, OpenMetrics fixes, systemd readiness reporting, and SLSA build attestations on release artifacts. This is a project moving from hobbyist-friendly to operator-friendly, and accepting breakage to get there.

◆ Prediction

0.10.0 is already scoped by the deprecations announced in 0.9.1 — expect the flagged libdns providers to be removed and gandi to require Bearer tokens. Given the 0.9.x pattern, a feature release followed quickly by an integration fix is the likely shape.

Slack logo
Slack
COMMSCOLLAB
6.3

Slack is shipping its developer platform to coding agents, not only to developers.

◆ Current state

The developer changelog runs two tracks at once. One is a routine modernization wave across the client libraries: Bolt for JS reached v5, the Node SDK packages took coordinated major versions, and the CLI shipped twice in ten days. The other is newer and smaller in volume but larger in intent, aimed at AI tooling rather than at people writing apps by hand.

◆ Where it's heading

The MCP and Skills plugin is the clearest signal of where this is going: Slack is packaging its own platform knowledge for consumption by coding agents, and naming Claude Code and Cursor as the first targets rather than shipping a generic endpoint. Meanwhile the SDK work is clearing debt that would get in the way, dropping axios for native Fetch, removing the deprecated Workflow Steps from Apps feature, and raising the Node floor to 20. Modern runtime, fewer legacy surfaces, then agent access on top.

◆ Prediction

The plugin ships for two named agent clients today, so the obvious next step is broadening that list or folding the skills into the CLI itself. The entries do not indicate whether Slack intends the MCP server to reach runtime app behaviour or stay a build-time developer aid.

Alternatives to Maddy and Slack

Other Comms products tracked by Sparkpulse, ranked by recent ship velocity. Each card links to a full editorial trajectory and lets you pivot into a head-to-head comparison with either Maddy or Slack.

See all Maddy alternatives → · See all Slack alternatives →

Recent activity from Maddy and Slack

Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.

  1. 1d agoSlackAnnouncing the Slack MCP and Skills Plugin
  2. 2d agoSlackRelease: Slack CLI v4.6.0
  3. 11d agoSlackRelease: Slack CLI v4.5.0
  4. 17d agoSlackRelease: Bolt for JS v5
  5. 18d agoSlackRelease: Multiple Node Slack SDK package updates
  6. 19d agoSlackDesktop notifications now pull text from blocks first
  7. 2mo agoMaddymaddy 0.9.5 fixes nested pipeline logging and systemd reload reporting
  8. 3mo agoMaddymaddy 0.9.4 removes the maddyctl symlink and implicit run command
  9. 3mo agoMaddymaddy 0.9.3 patches an LDAP injection flaw in auth.ldap
  10. 4mo agoMaddymaddy 0.9.2 fixes an rspamd panic on unspecified tls_client
  11. 4mo agoMaddymaddy 0.9.1 flags libdns providers for removal in 0.10.0
  12. 4mo agoMaddymaddy 0.9.0 adds no-downtime configuration reloading

Frequently asked questions

What is the difference between Maddy and Slack?

They serve adjacent needs but don't currently overlap on shipped themes. Slack is currently shipping more aggressively (velocity 6.3 vs 0.0), with 1 editorial sparks in the last 30 days against 0. See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.

Is Maddy better than Slack?

Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. Slack is currently shipping more aggressively (velocity 6.3 vs 0.0), with 1 editorial sparks in the last 30 days against 0. For your specific use case, the alternatives sections above list other Comms products to evaluate alongside.

What are the best alternatives to Maddy?

Top Maddy alternatives in Comms are ranked by recent ship velocity. Browse the "Maddy alternatives" section above for the current picks, or visit /alternatives/maddy for the full list with editorial commentary on each.

What are the best alternatives to Slack?

Top Slack alternatives in Comms are ranked by recent ship velocity. Browse the "Slack alternatives" section above for the current picks, or visit /alternatives/slack for the full list with editorial commentary on each.