# How to set up Fastmail with a custom domain? > Fastmail needs 6 DNS records for your domain: 2 MX (in1-smtp at 10, in2-smtp at 20), 1 SPF and 3 DKIM CNAMEs. Individual costs 60 EUR a year. - URL: https://postelva.com/guides/fastmail-custom-domain-setup/ - Last updated: 2026-11-12 - Publisher: Postelva (https://postelva.com) Fastmail is the simplest of the paid providers to point a domain at: two MX records, one SPF and three DKIM CNAMEs. The exact values are below. **Quick answer — How to set up Fastmail with a custom domain?** Add your domain in Fastmail under Settings > Domains, then publish 6 records: MX in1-smtp.messagingengine.com (10) and in2-smtp.messagingengine.com (20), an SPF TXT with include:spf.messagingengine.com, and three DKIM CNAMEs fm1, fm2 and fm3. **Postelva** has a one-click Fastmail template that applies them. ## The six DNS records for a Fastmail domain *From Fastmail's default DNS records help page, read 12 November 2026. Replace example.com with your domain.* | Record | Type | Host | Value | Priority | | --- | --- | --- | --- | --- | | Mail 1 | MX | @ | in1-smtp.messagingengine.com | 10 | | Mail 2 | MX | @ | in2-smtp.messagingengine.com | 20 | | SPF | TXT | @ | v=spf1 include:spf.messagingengine.com ?all | - | | DKIM 1 | CNAME | fm1._domainkey | fm1.example.com.dkim.fmhosted.com | - | | DKIM 2 | CNAME | fm2._domainkey | fm2.example.com.dkim.fmhosted.com | - | | DKIM 3 | CNAME | fm3._domainkey | fm3.example.com.dkim.fmhosted.com | - | ## Steps for a domain bought outside Fastmail 1. **Register the domain** — Buy it in the Postelva client area and keep the DNS there. 2. **Open a plan that allows domains** — Individual, Duo, Family and the business Standard and Professional plans allow custom domains. The business Basic plan does not. 3. **Add the domain in Fastmail** — Go to Settings, then Domains, and add the domain you own. Fastmail displays the records it expects. 4. **Apply the Fastmail template** — In the DNS editor choose the Fastmail template, which sets the MX, SPF and DKIM records in one click. 5. **Recheck and create addresses** — Press Recheck DNS in Fastmail. The domain should read Active, MX records set. Then add addresses and a test message. *The Fastmail zone for example.com* ```dns example.com. MX 10 in1-smtp.messagingengine.com. example.com. MX 20 in2-smtp.messagingengine.com. example.com. TXT "v=spf1 include:spf.messagingengine.com ?all" fm1._domainkey.example.com. CNAME fm1.example.com.dkim.fmhosted.com. fm2._domainkey.example.com. CNAME fm2.example.com.dkim.fmhosted.com. fm3._domainkey.example.com. CNAME fm3.example.com.dkim.fmhosted.com. ``` ## Which Fastmail plans work with your own domain? **Every personal plan does; among the business plans, Standard and Professional do and Basic does not.** On the euro price page read on 12 November 2026, Individual cost 6 EUR a month or 60 EUR a year, Duo 10 EUR or 96 EUR a year, and Family 14 EUR or 132 EUR a year for up to 6 users. Business Standard cost 6 EUR per user per month and Professional 10 EUR. USD prices may differ and were not verified. Fastmail does not state a limit on the number of domains. Crypto is not an option: no crypto payment was found on Fastmail's pages. Fastmail also sells domains (.com, .net, .org, .io, .ac and .sh) to paid accounts older than 7 days, but it publishes no price outside checkout. Buying the domain separately keeps it in your control, as [what is a custom email domain](https://postelva.com/custom-email-domain/ "What is a custom email domain?") explains. ## Why is Fastmail's SPF value ?all and not ~all? **Fastmail's published value ends in ?all, a neutral result, whereas many providers publish ~all, a soft fail.** Copy Fastmail's value as written on its help page. If you already have an SPF record, add include:spf.messagingengine.com to it instead of creating a second one, because two SPF records on one name are invalid. The 10-lookup limit of RFC 7208 counts the include, so check your total in [how to create an SPF record](https://postelva.com/guides/spf-record-setup/ "How to create an SPF record for a custom domain"). The DKIM records use the pattern fm1, fm2 and fm3, each pointing to fm#.yourdomain.dkim.fmhosted.com. The older mesmtp._domainkey record applies only to domains hosted at Fastmail before 2018. For the logic of selectors see [how to set up DKIM](https://postelva.com/guides/dkim-setup/ "How to set up DKIM for a custom email domain"). Fastmail's DMARC value was not read on the pages Postelva opened, so write it using the staged method rather than a copied string. ## What other records does Fastmail document? **Fastmail documents six SRV records for auto-discovery, so mail apps find the right servers on their own.** They cover submission on port 465 (smtp.fastmail.com), IMAP on 993 (imap.fastmail.com), JMAP on 443 (api.fastmail.com), autodiscover on 443, CardDAV and CalDAV on 443. They are optional for receiving mail. The default TTL is one hour. An MX-only domain needs extra DNS for subdomain addressing (tag@username.domain). According to Postelva's count of 12 November 2026, Fastmail needs the fewest records of the three providers whose full lists are public here, 6 against 8 for Proton Mail and 11 for Mailbox.org. Postelva supplies one-click DNS templates for Proton Mail, Fastmail, Zoho Mail, Google Workspace and Microsoft 365, plus an SPF + DMARC template and a "no email" template for a domain that sends nothing, and the DNS editor supports free DNS hosting with A, AAAA, CNAME, ALIAS, MX, TXT, NS, SRV and CAA records, DNSSEC, and your own nameservers if you prefer (2 to 13). ## How do aliases and catch-all work on Fastmail? **Fastmail supports plus addressing, subdomain addressing and a wildcard alias.** Create the wildcard under Settings > My email addresses; a specific alias always wins over the catch-all. Giving each service a separate address lets you spot who leaked yours, a use described in [how to use a catch-all address and aliases](https://postelva.com/guides/catch-all-and-aliases/ "How to use a catch-all address and aliases on your own domain"). Mail at Fastmail is protected by TLS in transit but is not end-to-end encrypted by default. Your address stays portable, because moving away only means changing records; the method is in [how to move email to a new provider without losing mail](https://postelva.com/guides/move-email-provider-without-downtime/ "How to move email to a new provider without losing mail"). A .com at Postelva costs $12.49/year every year, usually within minutes of the top-up being credited. Fastmail uses two MX records for a custom domain, in1-smtp.messagingengine.com at priority 10 and in2-smtp.messagingengine.com at priority 20, plus three DKIM CNAMEs. ## Questions about Fastmail and custom domains ### Do I need a verification record for Fastmail? Not for an MX-only setup. The domain shows Active, MX records set after you press Recheck DNS in Settings > Domains. ### Can I use the Fastmail Basic business plan? No. Its pricing page does not allow custom domains on Basic. Pick Standard or Professional, or a personal plan. ### Does Fastmail take crypto? No crypto payment was found. You can still pay for the domain with BTC, USDT, USDC, ETH, SOL, LTC at Postelva and pay Fastmail by another method. ### Is the DKIM target the same for every domain? No. It contains your domain name: fm1.example.com.dkim.fmhosted.com for example.com. Replace the domain part. **In summary** - Fastmail needs 6 records: 2 MX, 1 SPF, 3 DKIM CNAMEs. - MX: in1-smtp.messagingengine.com (10) and in2-smtp.messagingengine.com (20). - SPF: v=spf1 include:spf.messagingengine.com ?all. - DKIM: fm1, fm2, fm3 _domainkey pointing to fm#.yourdomain.dkim.fmhosted.com. - Individual is 60 EUR a year; business Basic does not allow custom domains. - Postelva has a one-click Fastmail template; .com is $12.49/year every year. ## Sources 1. [Fastmail - Default DNS records](https://www.fastmail.help/hc/en-us/articles/360060591153) — Fastmail (read 2026-11-12) 2. [Fastmail pricing](https://www.fastmail.com/pricing/) — Fastmail (read 2026-11-12) 3. [Fastmail - Registering a domain through Fastmail](https://www.fastmail.help/hc/en-us/articles/5948732264335) — Fastmail (read 2026-11-12) 4. [Fastmail - Catch-all / wildcard aliases](https://www.fastmail.help/hc/en-us/articles/1500000277942-Catchall-Wildcard-aliases) — Fastmail (read 2026-11-12) --- Postelva: Postelva registers domain names for private email — the address you keep when you change provider — paid in crypto with no KYC: no ID, only one verified email per domain. It is run by DomaineGoat LLC, a company registered in Panama; domains are registered through its ICANN-accredited registrar partner. A .com costs $12.49/year, the same price every year.