Chanty
Chanty's feed is an HR statistics content mill, not a product changelog
Comparison · Comms
Gromox vs Stalwart
A side-by-side editorial comparison of Gromox and Stalwart — release velocity, themes, recent moves, and the top alternatives to consider.
Shared themes:imap
Gromox vs Stalwart: at a glance
What is Gromox?
Gromox is filling in Exchange Web Services fast enough to matter for non-Outlook clients.
Gromox ships a minor roughly every four to eight weeks and has moved from 3.0 to 3.9 in this window. The centre of gravity is EWS: 3.6 landed roughly two dozen operations at once — task CRUD, delegate management, calendar occurrences with timezones, full meeting invitation and cancellation lifecycle, read receipts — and every release since has extended or corrected it. Alongside that, 3.8 introduced a per-store split-process model for the Information Store and partial IMAP4rev2 support, and 3.9 made auto-accepted room bookings send confirmations and handle cancellations.
What is Stalwart?
Stalwart is chasing mail RFCs and its own storage layer at the same time
Stalwart ships roughly weekly, and the releases divide cleanly between standards implementation and correctness work. v0.16.18 turns toward resource control — bounds on decompressed inbound DMARC and TLS report size, a cap on RocksDB block-cache memory, column families tuned per access pattern, and a queue scheduler that stops rescanning from the earliest pending event. The preceding releases added IMAP UIDONLY, UIDBATCHES and MESSAGELIMIT, plus JMAP email push and VAPID.
Gromox vs Stalwart: editorial side-by-side
Gromox
2.5COMMS
Gromox is filling in Exchange Web Services fast enough to matter for non-Outlook clients.
◆ Current state
Gromox ships a minor roughly every four to eight weeks and has moved from 3.0 to 3.9 in this window. The centre of gravity is EWS: 3.6 landed roughly two dozen operations at once — task CRUD, delegate management, calendar occurrences with timezones, full meeting invitation and cancellation lifecycle, read receipts — and every release since has extended or corrected it. Alongside that, 3.8 introduced a per-store split-process model for the Information Store and partial IMAP4rev2 support, and 3.9 made auto-accepted room bookings send confirmations and handle cancellations.
◆ Where it's heading
The project is working outward from MAPI compatibility toward the protocols that non-Outlook clients actually speak. EWS is the clearest case, but the same pattern shows in IMAP (custom keywords, IMAP4rev2 commands, SENT* keywords fixed to test the Date header as the spec requires) and in AutoDiscover fixes that unblocked Thunderbird. A second, quieter thread is offloading format conversion to external tools — Pandoc for HTML/RTF, Chawan for HTML-to-text — rather than maintaining converters in-tree. Meeting and calendar handling generates the most fix traffic, which is what you would expect from the hardest part of an Exchange-compatible server.
◆ Prediction
Expect EWS coverage to keep expanding toward whatever operations remain unimplemented, since that has been the consistent destination of feature work for five releases. The split-process Information Store introduced in 3.8 is the other thread to watch — a config bitmask suggests further isolation work is planned rather than finished.
Stalwart
5.0COMMS
Stalwart is chasing mail RFCs and its own storage layer at the same time
◆ Current state
Stalwart ships roughly weekly, and the releases divide cleanly between standards implementation and correctness work. v0.16.18 turns toward resource control — bounds on decompressed inbound DMARC and TLS report size, a cap on RocksDB block-cache memory, column families tuned per access pattern, and a queue scheduler that stops rescanning from the earliest pending event. The preceding releases added IMAP UIDONLY, UIDBATCHES and MESSAGELIMIT, plus JMAP email push and VAPID.
◆ Where it's heading
Two threads run through every release. One is RFC coverage across IMAP, JMAP, CalDAV and WebDAV, implemented close to the specification including drafts. The other is a long tail of protocol-conformance fixes, many of them cases where JMAP and IMAP disagreed about the same state. The newest release adds a third: memory and scheduling limits, which is what a server codebase starts doing when deployments get large enough for defaults to hurt.
◆ Prediction
Expect continued RFC additions across the JMAP and IMAP surfaces, with more of the storage-tuning work that v0.16.18 started as RocksDB deployments scale.
Alternatives to Gromox and Stalwart
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 Gromox or Stalwart.
Proton Bridge
Proton Bridge spends its first release in ten weeks on crashes, memory bounds and dead code
Mux
Every manual control Mux ships now arrives with a Robots workflow that does it for you
Netcore Cloud
Netcore's feed remains a demand-generation channel; ten entries, zero product releases.
mailcow
mailcow's release notes are almost entirely upstream security currency.
Openfire
Openfire keeps its XMPP server current without changing what it is.
See all Gromox alternatives → · See all Stalwart alternatives →
Recent activity from Gromox and Stalwart
Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.
- 1d agoStalwartResource limits arrive for inbound reports and RocksDB caches
- 8d agoStalwartIMAP gains UIDONLY, UIDBATCHES and message-limit extensions
- 16d agoStalwartJMAP delivery push arrives; strict relays stop rejecting calendar mail
- 23d agoStalwartFix-only release: JMAP semantics and a credential escalation
- 26d agoGromox3.9 makes room bookings and EWS meetings properly actionable
- 29d agoStalwartVAPID lands for JMAP Web Push
- 1mo agoStalwartFreeBSD support, plus OAuth scopes for IMAP, SMTP and Sieve
- 1mo agoGromox3.8 splits the Information Store per store and extends IMAP
- 3mo agoGromox3.7 fixes shared calendars, EWS fields and Thunderbird discovery
- 4mo agoGromox3.6 lands the full EWS meeting, delegate and task surface ⚡
- 5mo agoGromox3.5 adds per-service listen directives and fixes notifications
- 6mo agoGromox3.4 adds pre-delivery junk shelving and tightens header handling
Frequently asked questions
What is the difference between Gromox and Stalwart?
Both compete on the same themes — imap — within Comms. Stalwart is currently shipping more aggressively (velocity 5.0 vs 2.5), with 0 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 Gromox better than Stalwart?
Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. Stalwart is currently shipping more aggressively (velocity 5.0 vs 2.5), with 0 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 Gromox?
Top Gromox alternatives in Comms are ranked by recent ship velocity. Browse the "Gromox alternatives" section above for the current picks, or visit /alternatives/gromox for the full list with editorial commentary on each.
What are the best alternatives to Stalwart?
Top Stalwart alternatives in Comms are ranked by recent ship velocity. Browse the "Stalwart alternatives" section above for the current picks, or visit /alternatives/stalwart for the full list with editorial commentary on each.