Comparison · facts checked 14 Oct 2026
Every domain in one inbox, with DMARC you can read.Fastmail is one of the best independent email hosts there is — polished apps, calendars and contacts, billed per user. SuperMailOS trades the extras for multi-domain focus: every domain converges into one inbox, aliases are free everywhere, and your DMARC reports land in a dashboard.
The short answer
Last updated . Fastmail details from public sources, 14 Oct 2026. Where they win comes first.
01 Side by side
An honest, current comparison. Where we're unsure of a competitor detail, we describe what SuperMailOS does rather than assert theirs.
| Feature | Fastmail | SuperMailOS |
|---|---|---|
| Product model | FastmailIndependent hosted email with calendars and contacts; billed per user, tiered | SuperMailOSHosted email, per mailbox — every domain converges into one inbox |
| Entry price | FastmailPer user: Basic, Standard, Professional. Custom domains from Standard (US-dollar prices not quoted: see sources) | SuperMailOSPro $4/mo per mailbox ($3 annual) · Business $6/mo ($5 annual) |
| Custom domains | FastmailPartlyStandard and Professional plans, not Basic | SuperMailOSYesEvery plan; Business is unlimited domains |
| Aliases | FastmailYes“Hundreds of additional email addresses” and Masked Email | SuperMailOSYesUnlimited and free, on every domain |
| IMAP & SMTP | FastmailYesFull IMAP/SMTP | SuperMailOSYesEvery plan (993/465, SSL) |
| Two-factor auth | FastmailYesSupported | SuperMailOSYesTOTP 2FA + session management |
| Email authentication | FastmailYou add the DNS records Fastmail provides | SuperMailOSRecords generated from the server zone and checked live, plus automatic warm-up |
| DMARC report dashboard | FastmailNot listed on Fastmail's pricing page | SuperMailOSYesAggregate reports parsed into a dashboard |
| Calendars & contacts | FastmailYesBuilt in | SuperMailOSNoEmail-focused |
Fastmail facts from Fastmail’s own pages: Fastmail pricing · checked 14 Oct 2026
02 Honestly
If any of these describe you, Fastmail is probably the right call — and that's fine.
01
Years of polish, excellent native apps, a clear privacy stance and a reputation earned over a long time.
02
Calendars, contacts and masked email are built in — a genuinely broader personal-productivity story than email alone.
03
Fastmail says it offers "hundreds of additional email addresses" plus Masked Email, so one person can keep many addresses without extra seats.
01
Every domain converges into one inbox with aliases free, and Business is unlimited domains on one bill — not a per-user tier you climb as addresses multiply.
02
Aggregate DMARC reports are parsed into a dashboard instead of arriving as XML attachments, and new domains warm up automatically.
03
Publish records on Cloudflare, DigitalOcean, Linode, Vultr, Hetzner DNS or Spaceship in a click, and watch them verify before you send.
04
Deliverability, unlimited aliases and IMAP/SMTP are included rather than gated behind a higher tier.
Which one fits you
Fastmail is an easy recommendation if you want a polished personal or team mailbox with calendars and contacts. If your need is many domains in one inbox, with DMARC visibility and free aliases everywhere, SuperMailOS is built for exactly that — and IMAP/SMTP and 2FA are a tie, so you give up neither.
SuperMailOS is hosted business email: we run the mail server, the sending IPs and the deliverability work, so there's nothing to self-host and no server to keep alive.
Still comparing? Ask your AI — we've written the question.
03 Switching
Your domain stays where you bought it. Nothing to install, and your old mail can come with you.
One click on Cloudflare, DigitalOcean, Linode, Vultr, Hetzner DNS and Spaceship. Anywhere else, we show you exactly what to paste.
A mailbox for each person, and free aliases for everything else — hello@, billing@, support@.
Use the web app, or Apple Mail, Outlook and Thunderbird over IMAP.
04 Questions
Something else? Write to us — a real person answers, usually the same day.
Try it free for 14 days. No card, and your domain stays yours.