Email Deliverability Test

How do I test if my email goes to spam?

Reviewed by Prabath Thalangama · Last updated October 23, 2026

Send a real message to a one-time address and check what arrived. This deliverability test verifies SPF for the sending IP, the DKIM signature and DMARC alignment, looks the sending IP up on four major blacklists and in reverse DNS, checks basic content signals, and scores the result from 0 to 10.

A DNS lookup tells you what you published. This test tells you what your mail system actually does with it: which IP really sent the message, which domain signed it, and whether the From address lines up with either. It catches problems a record check cannot, such as a relay that rewrites the envelope sender or a marketing platform that signs with its own domain.

The score is additive, in the style of mail-tester.com. The full points table is on the methodology page.

How do I run an email deliverability test?

Open the page to get a unique test address. It is valid for 30 minutes.
Send an email to it from the server, account or platform you want to test. Send a realistic message rather than a one-word test, because the content checks look at the subject and body structure.
Wait for the report. It appears once the message is received and analysed.
Fix what failed, get a new address and send again to confirm.

How to read the results

Score (0-10): SPF pass 2, DKIM valid 2, DMARC aligned 2, sending IP not blacklisted 2, PTR record present 1, no content problems 1.
SPF: The SPF result (pass, fail, softfail, neutral, none, permerror or temperror) for the IP that connected to us and the envelope sender (MAIL FROM) it used.
DKIM: Whether a DKIM signature on the message verified against the public key in DNS. A message altered after signing, or a key missing from DNS, fails here.
DMARC: The From domain's published DMARC policy, and whether SPF or DKIM passed for a domain that aligns with the From domain. Alignment is relaxed: subdomains of the same organisational domain count.
Blacklists: Whether the sending IPv4 address is listed on Spamhaus ZEN, SORBS, Barracuda or SpamCop. DNSBL error replies (127.255.255.x) are not counted as listings.
Reverse DNS: Whether the sending IP has a PTR record. Many receivers reject or penalise mail from IPs without one.
Content: Flags spam-trigger words in the subject (for example FREE, WINNER, ACT NOW), an all-caps subject, an HTML body without a plain-text alternative, and a missing Message-ID header.

Common deliverability problems and how to fix them

SPF fails or softfails for the sending IP

The server that actually delivered the message is not in your SPF record. Add the provider's include or the server's IP, then compare with the IP shown in the result.

v=spf1 include:_spf.google.com include:sendgrid.net -all

DKIM passes but DMARC is not aligned

The message is signed with the provider's domain (d=provider.net) rather than yours. Set up custom DKIM signing for your domain in the provider's settings so d= matches your From domain.

Sending IP has no PTR record

Ask whoever owns the IP (your hosting or cloud provider) to set reverse DNS to a hostname that resolves back to the same IP, typically the server's HELO name.

No plain-text alternative

Send HTML mail as multipart/alternative with both a text/plain and a text/html part. Most mail libraries and platforms have a setting for it.

Examples and command-line equivalents

Send a test from a Linux server with swaks

swaks prompts for the password.

swaks --to <test address from this page> --from [email protected] \
  --server smtp.example.com:587 --tls --auth-user [email protected]

Check the same records from the command line

dig +short TXT example.com | grep spf1
dig +short TXT selector._domainkey.example.com
dig +short TXT _dmarc.example.com
dig +short -x 203.0.113.25

Frequently asked questions

Why is my email going to spam?

The most common causes are failing SPF, DKIM or DMARC alignment, a sending IP on a blacklist, missing reverse DNS on the sending server, and content that looks like bulk mail. This test shows which of these apply to your message.

Does a 10/10 score guarantee inbox placement?

No. It means the technical authentication and reputation checks are clean. Mailbox providers also weigh sender reputation history, engagement and complaint rates, which no external test can see.

How long is the test address valid?

30 minutes from when the page created it. After that the test expires and you need a new address.

Is the test email stored?

The message is only used to produce your report. Do not send sensitive content to the test address; a normal-looking sample is all that is needed.