fastmail.us is a free email provider

fastmail.us is a consumer mailbox provider, so anyone can open an address there in a minute.

Free provider Spoofable

79 /100

Strong

Email authentication report card

What fastmail.us publishes in DNS to stop other people sending mail in its name, read record by record.

1 pass 4 weak

Can mail be forged as this domain?

Yes, a forgery is delivered

DMARC is set to p=none, which only asks for reports, so a receiver that honours what this domain publishes is not told to reject a message with it in the From header, and delivers it.

  • Weak

    SPF ~all

    The record ends in ~all. Mail from a host outside the list is only marked, not rejected, so it usually still arrives.

  • Weak

    DMARC p=none

    A DMARC record is published, but p=none only asks for reports. Receivers are told to deliver failing mail anyway, so this stops no forgery.

    A checker that reports "DMARC found" here is telling you nothing useful.

  • Weak

    MTA-STS testing

    A policy is published in testing mode. Failures are reported but delivery still goes ahead over an unverified connection.

  • Weak

    DNSSEC Not signed

    The zone is not signed. A resolver has no cryptographic way to tell a real answer from a forged one.

  • Pass

    TLS-RPT Published

    Sending servers have an address to report failed TLS deliveries to.

Why it scores 79?

  1. Accepts mail through 2 MX hosts.
  2. Mail is handled by a mailbox provider we recognize.
  3. A website answers on this domain.

What to publish to close the gaps

The records fastmail.us is missing, in the order they are worth doing. Owner names are written out in full, so they work whether your DNS panel wants a full name or a relative one.

  1. Tighten SPF to -all

    Namefastmail.us
    TypeTXT
    Valuev=spf1 <your existing mechanisms> -all

    Keep the mechanisms you already have and change the final qualifier. Anything softer leaves the forgery path open.

  2. Move DMARC off p=none

    Name_dmarc.fastmail.us
    TypeTXT
    Valuev=DMARC1; p=quarantine; pct=100; rua=mailto:[email protected]

    p=none blocks nothing. Once your reports show every legitimate sender passing, raise the policy to quarantine and then to reject.

  3. Switch MTA-STS to enforce

    Valuemode: enforce

    Change mode in https://mta-sts.fastmail.us/.well-known/mta-sts.txt and bump the id in the TXT record. Testing mode reports failures but still delivers.

  4. Sign the zone with DNSSEC

    Turn DNSSEC on with your DNS provider, then publish the DS record it hands you at your registrar. Every record above is only as trustworthy as the answer that carries it, and signing the zone is what makes the answers verifiable.

Questions about fastmail.us

Every answer below is generated from the stored record for this domain.

Is fastmail.us a disposable email domain?
No. fastmail.us is a consumer mailbox provider, so addresses are permanent, but anyone can open one in a minute.
Is fastmail.us spoofable?
Yes, a forgery is delivered. DMARC is set to p=none, which only asks for reports, so a receiver that honours what this domain publishes is not told to reject a message with it in the From header, and delivers it.
Does fastmail.us publish SPF and DMARC?
fastmail.us publishes an SPF record, though it does not end in -all, so hosts outside the list are not treated as forgeries. DMARC is published but set to p=none, which only asks for reports. It looks like protection and is not.
Who handles email for fastmail.us?
Mail for fastmail.us is handled by Fastmail, which carries 134 other domains we track.
How old is the fastmail.us domain?
The registry for .us does not publish a registration date we can read, so we do not state an age.
How do I block fastmail.us on my signup form?
We do not classify fastmail.us as disposable, so blocking it outright would turn away real people. If you want to act on it, decide on the signals listed above rather than the name.
Can I trust email from fastmail.us?
fastmail.us scores 79 out of 100, which is a strong band. The score is a summary of the classification, infrastructure, authentication, reputation and lifecycle signals we hold, not a judgment about any individual sender at that domain.

Last verified . We recheck every domain on a schedule, and this report changes only when its records or its verdict do.