Comparison
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- 2 min
- Updated
- 14 Oct 2026
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- 4
Comparison
SuperMailOS vs Microsoft 365
Email-only savings vs the Office bundle — the honest math.
2 min read · 14 Oct 2026 · 4 sections
Microsoft 365 is what most companies already run — Word, Excel, Teams, and Exchange Online in one per-seat subscription. If your org genuinely uses the Office bundle, it's often the cheapest way to buy all of it at once. The question this page answers: what if you only need great business email?
| Microsoft 365 | SuperMailOS | |
|---|---|---|
| Price | Business Basic: $7 a user a month, list price from 1 July 2026 (was $6); $5.40 without Teams | Per mailbox: Pro $4/mo ($3 annual, 3 domains), Business $6/mo ($5 annual, unlimited domains) |
| What you’re buying | Microsoft’s apps, Teams and Exchange email in one per-user plan | Business email only — inbox, aliases, IMAP/SMTP, deliverability setup |
| Aliases | Up to 400 per user, “no additional fees or licenses” | Unlimited, free, every domain |
| Shared mailboxes | No license needed up to 50 GB | Counts as one mailbox; teammates get access at no extra cost |
| Multiple domains | Typically up to 5,000 domains per subscription | Every domain in one inbox, independently authenticated; Pro up to 3 domains, Business unlimited domains |
Microsoft 365 facts from Microsoft 365’s own pages: Microsoft 365 pricing, Microsoft: email aliases, Microsoft: shared mailboxes, Microsoft: domains FAQ · checked 14 Oct 2026
Where Microsoft 365 wins
- The bundle is the value. Desktop Office + Teams + OneDrive at business pricing is hard to assemble separately for less — if people actually use them.
- Enterprise everything. Compliance, eDiscovery, legal hold, conditional access — the admin surface is enormous and mature.
- Everyone knows Outlook/Teams. Zero onboarding friction in Microsoft-native orgs.
- Generous with addresses. Up to 400 aliases per user with no extra fee, and shared mailboxes need no license up to 50 GB (Microsoft’s own docs). If role addresses are your main worry, 365 already handles most of it.
Where SuperMailOS wins
- Email without the bundle tax. Seats that only need email ( support, ops, contractors ) cost $3–$6 a month, against $7 a user for Business Basic.
- No per-user address cap. Unlimited free role addresses on every domain, delivering into real inboxes.
- Multi-domain by design. Every product's mail in one inbox, with per-domain authentication and a per-domain deliverability view.
- Deliverability setup operated. Records from the mail server's zone, DKIM signing, DMARC parsing, warm-up and automatic pauses on bounce or complaint spikes, visible per domain.
Which one fits you
Company lives in Excel and Teams: 365, no contest. Email-heavy operations, many domains, or seats that never open Office: the per-mailbox math favors SuperMailOS quickly — see the plans.
FAQ
Does SuperMailOS work with Outlook?
Yes — standard IMAP/SMTP. Connect Outlook or any client; the managed deliverability is on the sending infrastructure side.
Can I run both — 365 for the office, SuperMailOS for products?
A common pattern: keep 365 for suite users, put product/support domains on SuperMailOS. Each domain's mail lives where it fits, with authentication handled on ours.
What about shared mailboxes?
Both have them. On Microsoft 365 a shared mailbox needs no license up to 50 GB. On SuperMailOS a shared mailbox like support@ counts as one mailbox and giving teammates access costs nothing extra; aliases are free on top.