Domain authentication is the sender's credibility verification process. It helps the email recipient identify whether the email is actually sent from the sender it claims to come from. It has an immensely positive impact on sender reputation and email deliverability by filtering out spam and fraud.
Internet service providers (ISPs) cannot trust messages that don't have authentication set up, as they cannot be certain about the source of the message. The most common email authentication standards are SPF, DKIM, and DMARC.
Mailercloud's domain authentication flow has three stages — Add domain → Connect → Verify — and you can see which stage you're on at the top of the screen throughout.
Go to Account → Settings → Domains.
You'll land on the Authentication page, which has three tabs: Domains, Sender Management and Reply IDs.
On the Domains tab, click Add Domain.
On the Add your sending domain screen, type the domain you'll send from in the Domain name field (for example, yourdomain.com).
Click Add domain & Verification.
You no longer need to select your domain provider from a list. Mailercloud scans your domain's DNS as soon as you submit it, detects who hosts your DNS, and generates instructions personalised to that provider instead of generic ones.
Once the domain is added, you move to the Connect stage, where you'll see the Add DNS records for yourdomain.com screen.
Your detected DNS host, shown in a blue banner at the top — for example, "Your DNS is hosted at Cloudflare — records go in your domain → DNS → Records → Add record." Next to it is a button that opens that provider's DNS manager directly (Open Cloudflare DNS Manager, Open Amazon Route 53 DNS Manager, and so on).
Step-by-step guide and Watch & Learn links, if you'd like the written walkthrough or the video.
A Share button in the top right — use this to send the record set to whoever manages your DNS, such as your developer or IT team, so they can add the records without logging in to your Mailercloud account.
The records table, showing the Type, Name / Host, Value and Status of every record you need to add.
Each record is listed with a short explanation of what it does. Your values are unique to your account, so always copy them from your own screen rather than from this article.
1. Sending CNAME — Required
Type: CNAME
Name / Host: mc.yourdomain.com
Value: your account-specific value, ending in .mlrcloud.com
2. DKIM CNAME — Required
Type: CNAME
Name / Host: k1._domainkey.yourdomain.com
Value: dkim.mlrcloud.com
Proves your emails haven't been tampered with in transit.
3. Second DKIM CNAME — Optional
Type: CNAME
Name / Host: k2._domainkey.yourdomain.com
Value: dkim2.mlrcloud.com
Enables automatic DKIM key rotation for stronger security. Your domain will still verify without it, but we recommend adding it.
4. Link and image tracking CNAME — Required
Type: CNAME
Name / Host: an account-specific host such as imgwxxxxx.yourdomain.com
Value: the matching imgwxxxxx.mlrcloud.com value
Generated for your account and used for link and image tracking.
5. DMARC record — Required
Name / Host: _dmarc.yourdomain.com
Depending on your setup, this appears either as a TXT record with a policy value beginning v=DMARC1; or as a CNAME record pointing to dmarc.mlrcloud.com. Add exactly what your screen shows.
Enter only the short host name. Most providers automatically append your domain to whatever you type. If your screen says "Cloudflare auto-appends '.yourdomain.com' — enter only info1", then type only that short prefix, not the full host. Each record row shows this hint for your specific provider.
Editing a host name. Some rows have a pencil icon next to the Name / Host field. Use it only if your DNS setup requires a different prefix — otherwise leave the generated values as they are.
If you need help adding records at your provider, these guides will walk you through it:
GoDaddy — https://in.godaddy.com/help/add-a-cname-record-19236
Cloudflare — https://support.cloudflare.com/hc/en-us/articles/360019093151-Managing-DNS-records-in-Cloudflare
Hostinger — https://support.hostinger.com/en/articles/1583249-how-to-manage-my-dns-records-on-hpanel
HostGator — https://www.hostgator.com/help/article/manage-dns-records-with-hostgatorenom
Domain.com — https://www.domain.com/help/article/dns-management-how-to-update-dns-records
Add every record exactly as shown on your screen — and nothing extra. The records listed in Mailercloud are the complete set your domain needs. You don't need to create any additional records of your own.
Add every required record at your provider. The optional record can be skipped, though we recommend adding it.
Come back to Mailercloud. The Status column updates as each record is found — records change from Pending to Verified.
Tick the Records added checkbox at the bottom of the screen. The Authenticate this domain button is greyed out until you do.
Click Authenticate this domain.
DNS changes can take a little time to propagate. If a record still shows Pending immediately after you've added it, wait a few minutes and check again.
When verification succeeds, you'll land on the Domain verified successfully! screen, with all three stages — Add domain, Connect, Verify — marked complete.
From here you can:
Click Setup sender ID to go straight to adding the name and email address your subscribers will see, or
Click Back to domains to return to the domains list.
Your authenticated domain now appears on the Domains tab with a green Verified status and the date and time it was authenticated.
If a domain shows Failed. The domains list shows a refresh icon next to any failed domain. Fix the missing or incorrect record at your provider, then click the refresh icon to re-check. You can also click Details on any domain row to see its full record set and current status.
A verified domain lets you send; a sender ID is the name and address your subscribers actually see. To add one:
Go to Account → Settings → Sender Management (or click Setup sender ID on the verification success screen).
Click Add Sender.
In the Add a sender panel that slides open on the right, fill in:
From email address — the part before the @, with your verified Sender domain selected from the dropdown beside it
From name — what recipients see in their inbox
Reply to
Company address, City, State, Zip code and Country
Click Continue.
We'll send a verification email to that address. Click the link in it to confirm.
Once confirmed, the sender appears on the Sender Management tab with a green Verified status.
Anti-spam laws such as CAN-SPAM and CASL require you to include your contact information, including a physical mailing address, in every promotional email you send. That's why the address fields are part of this form.
Mailercloud restricts domains from all major ISPs and those with a strict DMARC policy, as sending from them affects campaign deliverability. Disposable email domains are also restricted.
Depending on whether your domain has a mailbox, there are three scenarios.
Case 1 — The domain has a mailbox. Add the domain by following the steps above.
Case 2 — The domain has no mailbox. Add a subdomain first, then follow the rest of the procedure.
Case 3 — There is no mailbox and you want to send using the domain. Add the following record as well:
Host: @
Type: MX
Points to: mail.mlrcld.com.
Priority: 10
This is the most common issue when adding DNS records at providers like Cloudflare and GoDaddy. To speed things up, disable the proxy status for these records in your provider's panel. Proxied records can't be read correctly during verification.
If a record hasn't flipped to Verified after a few minutes, check the following:
The host name is doubled. Most providers append your domain automatically, so entering the full host creates something like mc.yourdomain.com.yourdomain.com. Check the hint under each Name / Host field and enter only the short prefix where it says to.
The record type is wrong. Each row shows whether it's a CNAME or a TXT record. A CNAME added as a TXT record won't verify.
The value was pasted with extra characters. Use the copy icon next to each value rather than selecting the text by hand, and check for stray spaces or a trailing dot.
DNS hasn't propagated yet. Changes usually appear within minutes but can take longer at some providers. Wait, then re-check.
If your provider rejects a record because one with the same name already exists, check whether the existing record is still in use. Delete it only if it's obsolete — otherwise contact our support team before removing anything, so we can check it won't break your current mail flow.
I'm asked to authenticate my domain. What is domain authentication? It's a verification process that confirms an email is sent by a genuine sender, which protects your reputation and improves inbox placement.
Will domain authentication affect my current email-sending potential? No. Domain authentication will not affect your current email-sending potential.
How many domains can I authenticate in a plan? As many as you want. There's no limit on authenticated domains in any plan.
Do I need to select my domain provider when adding a domain? No. Mailercloud scans your domain's DNS automatically and detects your provider, then shows instructions tailored to it, along with a button that opens that provider's DNS manager.
Do I need to add an SPF record? No. Mailercloud does not provide an SPF TXT record as part of domain authentication. The records shown on your DNS records screen are the complete set — add those and nothing else.
What is the record marked "Optional"? That's the second DKIM record (k2._domainkey). It enables automatic DKIM key rotation for stronger security. Your domain verifies without it, but we recommend adding it.
Someone else manages our DNS. Can I send them the records? Yes. Use the Share button at the top right of the DNS records screen to send the full record set to your developer or IT team.
Why is the "Authenticate this domain" button greyed out? You need to tick the Records added checkbox first, which confirms you've added the records at your provider.
My domain shows Failed. What do I do? Open Details to see which records are missing or incorrect, correct them at your provider, then click the refresh icon next to the domain on the Domains tab to re-check.
Can I use my domain before adding a sender ID? The domain needs to be verified and you need at least one verified sender ID before you can send a campaign from that domain.
If you run into any trouble while authenticating your domain or adding a sender ID, reach out to our support team through the in-app chat or email us at [email protected] — we're happy to help.
Happy emailing! 🚀
