ChainMail compared
ChainMail next to Exchange Online, Google Workspace, Zoho Mail.
Review draft. Competitor cells are unchecked; “To be checked” marks a gap on purpose.
| ChainMail | Exchange Online | Google Workspace | Zoho Mail | |
|---|---|---|---|---|
| Run it on your own hardware | YesA single server, or hosted by us | No | No | No |
| Classic Outlook connects with no plugin | Yes | Yes | PartlyNeeds Google's sync plugin | PartlyMail by IMAP with no plugin; calendar/contacts need ActiveSync or Zoho add-in |
| Webmail included with every mailbox | Yes | Yes | Yes | Yes |
| IMAP, POP3 and ActiveSync alongside Outlook's own protocols | Yes | YesIMAP/POP3 and Exchange ActiveSync available; EAS on by default | PartlyIMAP/POP via OAuth only; Google Sync (ActiveSync) ended for accounts in 2025 | PartlyIMAP, POP and ActiveSync; ActiveSync only on paid business plans |
| Calendar syncing to phones, tablets and Outlook | Yes | Yes | Yes | Yes |
| Contact syncing to phones, tablets and Outlook | Yes | Yes | Yes | Yes |
| Device approval for the email client (not one-time codes) | PartlyOptional, for Rivet-only mailboxes: each Rivet device is approved once and re-approved every 30 days. Other clients are blocked for those mailboxes, not second-factor protected. Phone approval is still being proven | PartlyActiveSync device allow/block/quarantine rules; not Outlook desktop | To be checked | To be checked |
| Any CalDAV or CardDAV app can use your calendar and contacts | Yes | To be checked | PartlyCalDAV and CardDAV supported but OAuth 2.0 only; no VTODO/MKCALENDAR | PartlyCalDAV and CardDAV documented; no VTODO, organisation address book not exposed |
| Phones and tablets sync natively, with no extra app | Yes | Yes | YesAdd Google account in iOS Mail/Calendar/Contacts; Android native; admin can restrict | PartlyNative sync via ActiveSync, paid business plans only |
| Aliases and forwarding per mailbox | Yes | YesExtra SMTP addresses per mailbox and per-mailbox forwarding documented | YesUp to 30 aliases per user; forwarding not separately fetched | YesPer-user email aliases route to primary mailbox; admin console |
| DKIM, SPF and DMARC for the mail you send | Yes | YesSPF, DKIM signing and DMARC records documented for custom domains | YesSPF, DKIM (Admin console) and DMARC (DNS record) documented | YesDKIM, SPF and a DMARC generator in the admin console |
| Every message can be copied to an archive (journaling) | Yes | YesJournaling to an external mailbox is documented | YesJournal copies of mail can be sent to a third-party archive address | YesEmail journaling available in Zoho Mail |
| Mail waits and is delivered if the main server is unreachable | Yes | PartlyOutbound retried about 24h, then NDR; hosted service, no queue-for-your-server | To be checked | To be checked |
| Mail store kept as three copies on three different hosts | Yes | YesEach mailbox database copied across datacenters (3 copies; another page says 4) | To be checked | To be checked |
| Moving over from Exchange (mail by IMAP; calendars and contacts imported separately) | Yes | YesCutover, staged, hybrid and IMAP migration paths documented | YesMigrates Exchange mail, calendar, contacts (GWMME/data import); IMAP mail only | YesAdmin Console migrates Exchange mail, contacts, calendars via EWS; IMAP mail only |