Authenticate Your Sending Domain

Before you can send from your own domain, three DNS records need to exist. They prove to Gmail, Outlook and everyone else that we are allowed to send on your behalf — without them your mail lands in spam, or is rejected outright.

Your time About 10 minutes Then waiting 15 min – 24 hrs You need Access to your DNS Records 3 to add

1Find where your DNS lives

This is usually wherever you bought your domain, or whoever hosts your website. If you are not sure, ask whoever set up your website — or look for a login at one of these:

ProviderWhere to go
GoDaddyMy Products → Domain → DNS → Manage Zones
CloudflareSelect your domain → DNS → Records
NamecheapDomain List → Manage → Advanced DNS
Google Domains / SquarespaceMy Domains → DNS → Custom records
AWS Route 53Hosted zones → your domain → Create record
cPanel hostingZone Editor → Manage
A common confusion

Your DNS is not always at the company you bought the domain from. If you have ever “pointed your nameservers” somewhere — at Cloudflare, or a web host — then that is where these records go. Adding them in the wrong place does nothing at all.

2Add the DKIM record

DKIM is a cryptographic signature on every message. It is the record that matters most: it is what actually proves the mail is yours. We generated a key for you — the exact value is shown in your dashboard under Manage Senders.

Record 1 of 3 · DKIM
TypeCNAME
Nameom1._domainkey
Valueom1.yourdomain.com.dkim.openmailers.com
TTLAutomatic, or 3600
Why a CNAME rather than the key itself

A CNAME points at a record we host, so when the key is rotated — which is good practice every year or two — it happens on our side and you never touch your DNS again. If your DNS provider cannot create a CNAME at that name, your dashboard also shows a direct TXT version you can paste instead. Either works.

Do not type your domain into the Name field

Most providers add your domain automatically. Enter om1._domainkey and it becomes om1._domainkey.yourdomain.com. If you type the full name you will end up with om1._domainkey.yourdomain.com.yourdomain.com, which will not work. Cloudflare and Route 53 show you the final name — check it before saving.

3Add the SPF record

SPF lists who may send using your domain. You need exactly one SPF record — two is worse than none, because receivers treat it as an error and ignore both.

If you have no SPF record yet

Record 2 of 3 · SPF, new
TypeTXT
Name@
Valuev=spf1 include:spf.openmailers.com ~all

If you already have one

Look for an existing TXT record starting v=spf1. Edit it — do not add a second. Insert include:spf.openmailers.com before the ~all or -all at the end:

before — you also send through Google Workspace
v=spf1 include:_spf.google.com ~all

after
v=spf1 include:_spf.google.com include:spf.openmailers.com ~all
The ten-lookup limit

SPF allows at most ten include: lookups. If you use several services — Google, a helpdesk, a CRM, us — you can quietly exceed it, at which point SPF fails for everything. If your record already has four or more includes, email it to support@openmailers.com and we will check it for you.

4Add the DMARC record

DMARC tells receivers what to do when a message claiming to be from you fails the other two checks, and asks them to send you reports. Gmail and Yahoo have required it from bulk senders since February 2024.

Record 3 of 3 · DMARC
TypeTXT
Name_dmarc
Valuev=DMARC1; p=none; rua=mailto:dmarc@yourdomain.com
Start at p=none, and mean it

p=none means “watch and report, reject nothing”. Start here for at least 30 days and read the reports. They will show you every service sending as your domain — usually including one or two you had forgotten.

Only once every legitimate source passes should you move to p=quarantine and later p=reject. Jumping straight to p=reject is the single most common way to make your own invoices and password resets vanish.

5Verify, and wait if you need to

Go back to Manage Senders in your dashboard and press Verify. If it passes, you can send. If not, DNS is often simply still propagating.

  • Usually live in 15–30 minutes.
  • Occasionally up to 24 hours, depending on your provider and previous TTL.
  • Press Verify again after an hour before assuming something is wrong.

To check the records yourself, use any online DNS lookup tool, or a terminal:

dig +short TXT om1._domainkey.yourdomain.com
dig +short TXT yourdomain.com
dig +short TXT _dmarc.yourdomain.com

6When it does not verify

What you seeUsually meansFix
DKIM not found Wrong name, or added at the wrong provider Check the final record name is om1._domainkey.yourdomain.com — not doubled. Confirm you edited DNS wherever your nameservers point.
DKIM found but does not match Value truncated on paste The key is long. Some panels silently cut it. Delete and re-paste, checking the end matches.
Multiple SPF records A second record was added instead of editing the first Merge them into one v=spf1 line and delete the extra.
SPF too many lookups More than ten include: entries Remove services you no longer use, or ask support to flatten it.
Verified, but mail still goes to spam Authentication is necessary, not sufficient Reputation is built by sending wanted mail consistently. See below.

7After you are verified

Authentication gets you to the inbox door. What keeps you inside it is who you send to and how often. The things that matter most, roughly in order:

  • Only send to people who asked. Purchased and scraped lists are the fastest route to being blocked, and they take everyone on the shared pool down with you.
  • Remove people who never open. A recipient who has ignored you for a year is a liability, not an opportunity — receivers read that silence as a signal.
  • Send on a steady rhythm. A predictable weekly send builds reputation. Six months of silence followed by a large blast does the opposite.
  • Make unsubscribing easy. Someone who cannot find the link presses “spam” instead, and that costs you far more.
  • Watch your first campaigns. A bounce rate above 2% or complaints above 0.1% means something is wrong with the list.
One more thing worth knowing

Some of your recipients’ addresses will not exist. We record those permanently and will not attempt them again, on any campaign — that protects your reputation and everyone else’s. You do not need to clean them out of your list by hand; we simply skip them.

Still stuck? Email your domain name to support@openmailers.com and we will look at your DNS with you.