FastMail mailbox provider

According to Live Direct Marketing's daily Tranco top-1M scan (July 13, 2026), FastMail is the mailbox provider for 1,576 domains — 0.24% of 658,711 domains with MX records. Detection method: primary MX record (lowest preference).

Key facts

FastMail is a paid email hosting and mailbox provider operated independently as a commercial service. Unlike free consumer email providers, it serves organisations seeking a hosted mailbox solution with privacy and independence from platform surveillance.

When surveyed across large website populations, FastMail appears most often among smaller and mid-market sites, concentrated in the .com namespace, and with stronger adoption in global and US regions. It is frequently found alongside Amazon SES deployments, where organisations use SES to send outbound mail and FastMail to host their operational inboxes. This pattern means that anyone testing email deliverability, especially in the SES ecosystem, will benefit from understanding how their authentication and reputation perform against FastMail recipients.

Where FastMail sits in the Tranco ranking

Tranco rank bandDomainsShare of its base
Top 1,00010.1%
Top 10,000211.3%
Top 100,00019712.5%
Top 1,000,0001,16674.0%
Unranked19112.1%

Top-level domain split

TLDDomainsShare
.com71445.3%
.org16510.5%
.net1479.3%
.io623.9%
.me261.6%
.co.uk231.5%
.dev201.3%
.tv191.2%
.co191.2%
.app181.1%

What FastMail users also use

Cross-tabulated from the same daily snapshot — the other email services seen on the same 1,576 domains.

TypeServiceDomainsShare of FastMail users
ESPAmazon SES1046.6%
ESPMailgun805.1%
ESPSendGrid (Twilio)412.6%
ESPMailchimp412.6%
ESPPostmark352.2%
ESPMailerSend301.9%
ESPHelp Scout291.8%
ESPZendesk261.6%
ESPMailjet (Sinch)241.5%
ESPMandrill211.3%

FastMail's role in SES-centric email architectures

The co-occurrence of FastMail with Amazon SES across smaller and mid-market deployments reveals a common operational pattern: organisations configure SES as their outbound sending engine for transactional mail, notifications, and marketing content, whilst maintaining their operational and support email on a hosted mailbox service like FastMail. This split reflects practical preferences for reliability and vendor independence. For senders, this means FastMail is an important validation point: if your DKIM, SPF, and DMARC configuration performs well with FastMail recipients, you are likely to perform well with the broader class of organisations using SES for outbound mail.

See the full FastMail data page (KPI cards, trend, sample domains) →

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Frequently asked questions

Should I test email deliverability against FastMail?

Yes, particularly if your audience includes small-to-medium organisations or if you deploy via Amazon SES. FastMail's prevalence in that segment—especially alongside SES—makes it a representative reference point for validating that your authentication, reputation, and sending practices function correctly across hosted mailbox providers.

How many domains use FastMail?

1,576 domains in the Tranco top-1M use FastMail as their mailbox provider as of July 13, 2026 (0.24% of domains with MX records), according to Live Direct Marketing's daily DNS scan.

Is FastMail common enough to affect email deliverability testing?

FastMail accounts for 0.24% of domains with MX records in the top 1M. Whether you should seed a test mailbox there depends on how much of your audience it represents — the co-usage table above shows the services it appears alongside most.

Which countries or TLDs use FastMail most?

FastMail's largest TLD is .com (45.3% of its domains); it appears across 167 TLDs in total.

Other mailbox providers

Self-Hosted (22.44%)Google Workspace (21.79%)Microsoft 365 (16.74%)Unknown / Other (7.54%)Generic / unmatched (mx*.*) (2.57%)Proofpoint (1.90%)Generic / unmatched (mail.*) (1.75%)Yandex 360 (1.64%)Cloudflare Email Routing (1.60%)Mimecast (1.52%)