The Microsoft 365 email alternative
you actually own.
Microsoft 365 keeps your mailboxes inside Microsoft's tenant, licensed per seat for as long as each person works there. Vectis Mail puts them on your server — full IMAP/SMTP mailboxes, your domains, DKIM/SPF/DMARC, webmail and a REST API, for a flat price instead of per-seat licensing. It's email infrastructure you own: it replaces the Exchange Online mailboxes in Microsoft 365, not the Office apps, Teams or SharePoint — that's the scope, and for most teams it's the part the bill is really for.
At a glance
Email-to-email comparison: Vectis Mail vs the Exchange Online half of Microsoft 365. Current as of June 2026.
| Vectis Mail | Microsoft 365 (Exchange Online) | |
|---|---|---|
| What it is | Self-hosted email server (you run it) | Managed email inside Microsoft's cloud, part of a productivity suite |
| Pricing model | Flat per tenant — $0 Starter / $39 USD Pro per month | Per user, per month (scales with headcount) |
| Mailboxes | Unlimited (Pro); 25/domain on Starter | One licensed mailbox per paid user |
| Domains | Up to 3 (Starter) · unlimited (Pro) | Multiple domains per tenant |
| Where mail lives | Your server, your region, your jurisdiction | Microsoft's tenant + datacentres |
| Protocols | Standard IMAP / SMTP / POP3 + Roundcube webmail | Exchange / Outlook (IMAP/SMTP available, MAPI-native) |
| Mailbox storage | Bounded only by your disk | 50 GB (Plan 1) / 100 GB (Plan 2) per mailbox |
| REST API for sending | Yes — domain-scoped keys, batch, attachments | Graph API (suite-wide, not a flat-priced sending service) |
| Inbound webhooks | Yes — HMAC-signed, retry-with-backoff | Via Graph subscriptions (more involved) |
| Spam filtering | Rspamd + optional ClamAV, your own rules | Exchange Online Protection (managed) |
| Office apps (Word/Excel/PPT) | No — email only | Yes (Standard/Premium) |
| Teams / SharePoint / OneDrive | No — email only | Yes |
| Calendar / contacts | Not yet (Phase 4 roadmap) | Yes (full Exchange calendaring) |
| Vendor compliance attestations | You are the data custodian | SOC 2 / ISO 27001 / HIPAA BAA |
| Lock-in | Standard protocols, data in your Postgres + filesystem | Microsoft tenant; migration is a project |
Microsoft 365 / Exchange Online pricing and storage retrieved 21 June 2026 from Microsoft. See sources below. Vectis Mail figures per /pricing.
Why teams move to Vectis Mail
Where per-seat email licensing starts to hurt.
- Email is the part of Microsoft 365 you actually use, and you're paying per seat for mailboxes you could own outright.
- Your headcount is growing and the per-user bill grows with it — a flat $39/month stops the linear climb.
- Data sovereignty, residency, or jurisdiction matters: your mail belongs on a server you control, in a region you choose, not in Microsoft's tenant.
- You want to be immune to tenant-level outages and provider lock-in — standard IMAP/SMTP on your own domain, your data in your own Postgres.
- You're a developer or agency that wants a real sending API, inbound webhooks, and per-domain control over the mail stack.
Own your mailboxes instead of licensing them
The framing Microsoft sells is a subscription: every employee is a "seat," and every seat is a recurring per-user charge for as long as they work there. Email — one of the oldest, most standardised technologies on the internet — gets billed like a SaaS product you rent forever.
Vectis Mail inverts that. You run the server, so a mailbox is just a row in your own database and a maildir on your own disk. Adding the 10th mailbox or the 500th costs the same: nothing extra. Your mail lives where you deployed it — on a VPS in the region and jurisdiction you chose — not inside a Microsoft tenant subject to Microsoft's terms, Microsoft's jurisdiction, and Microsoft's tenant-wide outages. When a provider has a bad day, a tenant-level Exchange Online incident takes everyone down at once; a server you control has a blast radius of exactly your own organisation.
And because it's all standard IMAP, SMTP, and POP3 on your own domain, there is no proprietary tenant to escape later. Migrating in is an IMAP sync; migrating out, if you ever wanted to, is the same. That's the difference between owning your mailboxes and licensing them.
Flat price vs per-seat licensing
Microsoft 365 and Exchange Online are priced per user per month, so the bill tracks your headcount. As of June 2026, Exchange Online Plan 1 is about $4/user/month(50 GB mailbox) and Plan 2 about $8/user/month (100 GB) on annual commitment. The fuller suites cost more, and Microsoft is raising prices from 1 July 2026: Business Basic goes to $7/user/month and Business Standard to $14/user/month — increases Microsoft has tied to bundling Copilot Chat and added features.
Vectis Mail is flat. Starter is $0 self-hosted (up to 3 domains, 25 mailboxes per domain); Pro is $39 USD per tenant per month for unlimited domains and unlimited mailboxes. Add a VPS to run it on and your fully-loaded cost is roughly $59/month whether you host 10 mailboxes or 500. Here's the same workforce, two billing models:
| Mailboxes | Vectis Mail Pro (+ ~$20/mo VPS) | Exchange Online Plan 1 (~$4/user) | M365 Business Standard (~$14/user, Jul 2026) |
|---|---|---|---|
| 10 users | $39/mo flat | ~$40/mo | ~$140/mo |
| 50 users | $39/mo flat | ~$200/mo | ~$700/mo |
| 200 users | $39/mo flat | ~$800/mo | ~$2,800/mo |
Honest caveat: the Business Standard column buys the whole Office suite + Teams, not just email — it's not a like-for-like mailbox comparison. The Exchange Online Plan 1 column is the closest apples-to-apples (email only), and even there Vectis Mail Pro — at ~$59/month all-in once the ~$20 VPS is included — pulls ahead past roughly 15 mailboxes. Per-user figures are Microsoft's; see sources.
Our scope: the mailbox half
One honest note on what Vectis Mail is — and isn't.
Vectis Mail is email infrastructure — full IMAP/SMTP mailboxes, your domains, sending API and webmail on a server you own. It replaces the Exchange Online mailboxes in Microsoft 365, not the wider suite: Word, Excel and PowerPoint; Teams; SharePoint; OneDrive. Teams that also need those run Vectis Mail for the mailboxes and keep a separate productivity suite alongside it, so the per-seat email licence stops scaling with headcount. That's the scope — deliberately email, done properly, and owned outright.
Migrating email off Microsoft 365
Because Exchange Online speaks standard IMAP, moving mailboxes to Vectis Mail is mechanical rather than proprietary. The typical sequence:
- Stand up Vectis Mail on a fresh VPS following the installation guide. Add your domain(s) and publish the DKIM/SPF/DMARC records it generates — but leave MX pointed at Microsoft for now.
- Create the mailboxes in Vectis Mail to match your existing users (or import them via the API for larger lists).
- Sync mail with
imapsync: copy each Exchange Online mailbox into Vectis Mail over IMAP. Run an initial pass days ahead, then a final delta sync at cutover. - Export calendar / contacts if you use them — Vectis Mail doesn't host calendaring yet (Phase 4 roadmap), so keep that on a suite or another tool. This is the step to plan around.
- Warm your sending IP if you send volume. A fresh VPS IP has no reputation; follow the dual-send warmup playbook so there's no day-one deliverability gap.
- Cut MX over to the Vectis Mail server once mailboxes are synced. Mail flows through Vectis Mail as DNS propagates.
- Verify and decommission: watch logs for a few days, then drop the Exchange Online email licences you no longer need.
A note on deliverability
Microsoft delivers your mail from warm, well-reputed IP pools, so you never think about it. On a fresh self-hosted VPS, your IP has no reputation on day one and major providers will throttle until you establish a pattern over 2–4 weeks. This is real, and we don't hide it.
The good news: you never switch cold. The dual-send warmup playbook keeps your current provider delivering while your own IP warms, so there's no day-one gap — just an overlap window you control. Once warm, a self-hosted IP with correct DKIM, SPF, DMARC, MTA-STS, and PTR records (all configured by default in Vectis Mail) can reach the major inboxes — at that point deliverability comes down to your IP reputation and DNS hygiene, not the platform you send from. Read the full honest answer onWill my mail land?
Frequently asked questions
Is there a self-hosted alternative to Microsoft 365 for email?
Yes. Vectis Mail is a self-hosted email server you run on your own VPS — Postfix, Dovecot, and Rspamd packaged with a REST API, a React admin UI, and an atomic update orchestrator. It replaces the email half of Microsoft 365 (the Exchange Online mailboxes): full IMAP/SMTP mailboxes, your own domains, DKIM/SPF/DMARC, andRoundcube webmail for a flat price instead of per-user-per-month licensing. It does not replace Office apps or Teams — that's a separate need.
Does Vectis Mail replace Office apps and Teams?
No — Vectis Mail is email infrastructure. It replaces Exchange Online, the mailbox and mail-delivery half of Microsoft 365, not Word, Excel, PowerPoint, Teams, SharePoint, or OneDrive. If your organisation also needs those, run Vectis Mail for the mailboxes and keep a separate productivity suite alongside it. Our scope is full IMAP/SMTP mailboxes on your own server, flat-priced.
How does Vectis Mail pricing compare to Microsoft 365 per-user licensing?
Microsoft 365 and Exchange Online are priced per user per month. Exchange Online Plan 1 is about $4/user/month and Plan 2 about $8/user/month on annual commitment; Microsoft 365 Business Standard rises to $14/user/month from 1 July 2026. That bill scales with headcount. Vectis Mail is flat: Starter is $0 self-hosted, Pro is $39 USD per tenant per month for unlimited mailboxes and domains. At 50 mailboxes, Business Standard runs about $700/month while Vectis Mail Pro plus a VPS is roughly $59/month — and the gap widens with every seat. See pricing.
Can I keep my domain and use standard email clients?
Yes. Vectis Mail uses standard IMAP, SMTP, and POP3 with your own domain, so Outlook, Apple Mail, Thunderbird, and mobile clients connect the way they do to any standard mail server, plus a bundled Roundcube webmail. Because it's standard protocols on your domain, there's no Microsoft tenant to lock you in — migrating in or out is plain IMAP sync, not a proprietary export.
Where does my email live with Vectis Mail versus Microsoft 365?
With Microsoft 365 your mailboxes live inside Microsoft's tenant, under their jurisdiction and subject to tenant-level outages. With Vectis Mail they live on a server you control, in the region and provider you choose. The message store is on your filesystem; the audit trail is in your own Postgres. For data-residency and sovereignty questions, the answer becomes "where did you deploy the server" instead of "trust the vendor."
Try Vectis Mail
Own your mailboxes. Flat price, your server, standard protocols.
Other Vectis Mail alternatives
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vs SendGrid →
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