Domain authentication connects your domain to SendX so inbox providers know your emails are legitimate. This article walks you through adding a domain in SendX and copying the DNS records you need to complete authentication.
When you'll need this
Read this article if you're setting up SendX for the first time, you're adding a new sending domain, you need to re-authenticate a domain after DNS changes, or you want to send from a different domain than you currently use.
Before you start
Make sure you have:
A domain you own (like yourbusiness.com)
Access to your domain's DNS settings, or contact information for whoever manages your DNS (IT team, web developer, hosting provider)
A few minutes to copy records from SendX and paste them into your DNS
If you don't have access to your DNS settings, SendX can email the instructions to someone who does. See the "Send instructions to someone else" section below.
What you'll be adding
SendX requires four DNS records to fully authenticate your domain:
Record Name | Type | Purpose |
sp-dkim._domainkey | TXT | Adds a digital signature to verify your emails are authentic |
sp-bounce | CNAME | Handles bounce processing for deliverability |
sp-track | CNAME | Enables click and open tracking |
_dmarc | TXT | Tells inbox providers how to handle unauthenticated emails |
You'll copy each record from SendX and add it to your DNS provider.
Step 1: Add your domain
Enter your domain name in the input field under "Sending Domain Authentication."
Click the "Add Sending Domain" button to proceed.
Step 2: View your DNS records
After adding your domain, SendX displays the four DNS records you need to add. Each record shows the record name, type, and value.
Click the copy icon next to each record to copy it to your clipboard.
Step 3: Add the DKIM record
The first record authenticates your emails with a digital signature.
Record details:
Name: sp-dkim._domainkey
Type: TXT
Value: Your unique DKIM key (starts with
v=DKIM1;k=rsa;s=email;h=sha256;p=...)
Copy this record and add it to your DNS provider as a TXT record.
Step 4: Add the bounce record
This CNAME record enables SendX to process bounces for better deliverability.
Record details:
Name: sp-bounce
Type: CNAME
Value: sp.sendpost.info
Copy this record and add it to your DNS provider as a CNAME record.
Step 5: Add the tracking record
This CNAME record enables click and open tracking in your campaigns.
Record details:
Name: sp-track
Type: CNAME
Value: track.sx30.email
Copy this record and add it to your DNS provider as a CNAME record.
Step 6: Add the DMARC record
The DMARC record tells inbox providers what to do when emails fail authentication.
Record details:
Name: _dmarc
Type: TXT
Value: v=DMARC1; p=none;
If you already have a DMARC record on your domain, you don't need to add another one. SendX will detect and use your existing DMARC policy.
Copy this record and add it to your DNS provider as a TXT record.
Step 7: Add records to your DNS
Log in to your DNS provider (GoDaddy, Cloudflare, Namecheap, etc.) and add all four records. Each provider has a slightly different interface, but you're generally looking for:
DNS settings or DNS management
Add record or Create record
Record type: TXT or CNAME (depending on the record)
Paste the values exactly as SendX provided them. Don't modify the records.
For step-by-step instructions for your specific provider, see:
Step 8: Wait for DNS propagation
After adding the records, DNS propagation can take anywhere from a few minutes to 24 hours. Most records propagate within a few hours.
Step 9: Verify your records
Once you've added the DNS records, check their status in SendX.
Click the three-dot menu next to your domain and select "Recheck Status."
SendX will check if your DNS records are properly configured. If successful, you'll see a confirmation message.
If verification fails, double-check that you copied the records exactly and that they've had time to propagate.
Send instructions to someone else
If you don't manage your own DNS, you can email the authentication instructions to your IT team or web developer.
Click the three-dot menu next to your domain and select "Send Instructions."
Enter the email address where instructions should be sent.
Click "Send" to deliver the instructions.
The recipient will receive an email with all the DNS records they need to add, formatted for easy copying.
Export all domain records
If you need a record of all your authenticated domains, you can export them.
Click the three-dot menu and select "Export All Sending Domains" to download your domain records.
Verification status
Your domain will show one of these statuses:
Status | Meaning |
Verified | DNS records are correctly configured. You can send from this domain. |
Not Verified | DNS records are missing or incorrect. Check your DNS settings. |
Pending | DNS records were recently added. Waiting for propagation. Try rechecking in a few hours. |
Troubleshooting
Records not verifying after 48 hours
Confirm you added all four records (sp-dkim._domainkey, sp-bounce, sp-track, _dmarc)
Check for typos or extra spaces when copying
Verify you selected the correct record type (TXT for DKIM and DMARC, CNAME for bounce and track)
Make sure you're adding records to the correct domain
DMARC shows failed but other records are verified
If you already have a DMARC record on your domain, SendX will show your existing policy. This isn't necessarily a problem. As long as the other records are verified and you have a DMARC record (either yours or the one from SendX), your emails will authenticate properly.
I added the records but nothing changed
DNS propagation can take time. Wait a few hours and use "Recheck Status" again. You can also use a tool like MXToolbox or DNSChecker to verify your records are publicly visible.
Only some records are verifying
Each record is checked independently. If some records verify but others don't:
Double-check the record type (TXT vs CNAME)
Verify the host name is exactly as shown in SendX
Check that the value was copied completely without truncation
Common questions
Can I authenticate multiple domains?
Yes. You can add as many domains as you need in SendX. Each domain requires its own set of four DNS records. There's no limit.
Do I need to authenticate subdomains separately?
Yes. If you want to send from mail.yourbusiness.com, you need to add that subdomain specifically in SendX. The root domain authentication doesn't automatically cover subdomains.
What if I already have a DMARC record?
Keep your existing DMARC record. SendX will detect it and use your current policy. Just make sure to add the other three records (sp-dkim._domainkey, sp-bounce, sp-track).
How long until I can start sending?
Once all four records show as verified, you can start sending immediately. There's no waiting period after verification.
Can I remove a domain later?
Yes. You can remove domains from your SendX account if you no longer need them. This won't affect your DNS records—you'll need to remove those separately if desired.
What does each record do?
sp-dkim._domainkey: Adds a cryptographic signature proving your emails are authentic
sp-bounce: Routes bounce notifications to SendX for deliverability tracking
sp-track: Enables open and click tracking in your campaigns
_dmarc: Tells inbox providers how to handle emails that fail authentication