Custom Domains
Add custom sending domains to send emails from your own domain (e.g., hello@yourdomain.com) instead of the default SendComms address. Custom domains improve deliverability and brand recognition.
How Custom Domains Work
Add your domain
Register your sending domain (e.g., mail.yourdomain.com) via the API or dashboard
Add one DNS record
Add the single DKIM TXT record we return to your DNS provider. Leave your MX records alone — your inbox stays exactly where it is.
Verify your domain
Trigger verification to check DNS propagation. Records usually appear within 30 minutes, though some providers take longer.
Start sending
Once verified, emails will automatically use your domain. You can also specify a custom "from" address.
Checking a domain before you add it
A domain can be held by only one SendComms account at a time. Check availability before you commit — the dashboard does this as you type.
/api/v1/domains/check?name=yourdomain.com{
"success": true,
"data": {
"name": "yourdomain.com",
"available": true,
"reason": null,
"message": "Domain is available."
}
}| reason | What it means |
|---|---|
null | Available — you can add it. |
taken_by_you | Already on your account. Use the existing domain instead of adding it again. |
taken | Registered to another SendComms account. If you own the domain, contact support@sendcomms.com and we will transfer it. |
in_use_upstream | Already configured on our mail infrastructure. Contact support if you own it. |
invalid | Not a valid domain name. |
Adding a domain that is not available returns 409 with the same reason field, so you can rely on the create call alone if you prefer.
Domain Status Values
| Status | Description |
|---|---|
| not_started | Domain added but verification not yet initiated |
| pending | Verification in progress, waiting for DNS propagation |
| verified | Domain verified and ready to send emails |
| failed | Verification failed. Legacy status — new domains stay pending until the DKIM record is found. |
| temporary_failure | DNS records temporarily not detected. Legacy status — retried automatically. |
Select Language
List all domains for your account.
curl -X GET \
https://api.sendcomms.com/api/v1/domains \
-H "Authorization: Bearer YOUR_API_KEY"Add a new sending domain. Returns DNS records that must be added to your DNS provider.
Request Body
| Parameter | Type | Description |
|---|---|---|
| name | string | Domain name (e.g., mail.yourdomain.com) |
| mode | string | send_only (default) adds sending to a domain whose inbox stays with your current provider — one DKIM record, your MX untouched. full also hosts this domain's inbox, which moves your MX to us and stops mail reaching your current provider. |
| region | string | Optional label kept on your domain record. All mail is currently sent from a single region, so this does not change routing. |
curl -X POST \
https://api.sendcomms.com/api/v1/domains \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"name": "mail.yourdomain.com",
"mode": "send_only"
}'Trigger DNS verification for a domain. Call this after adding DNS records.
curl -X POST \
https://api.sendcomms.com/api/v1/domains/YOUR_DOMAIN_ID/verify \
-H "Authorization: Bearer YOUR_API_KEY"Other Endpoints
Required DNS Records
Your inbox is not affected
SendComms sending domains are send-only. You add one DKIM record and nothing else. Do not change or remove your MX records — mail you receive keeps going to your current provider (Google Workspace, Zoho, Outlook, whatever you use today).
When you create a domain, the API returns the exact record to add. Domains verify on DKIM alone.
1 TXT record — required
Host scomms._domainkey, value starting v=DKIM1; k=rsa; p=…. Cryptographically signs your email so receivers can prove it really came from you. We use our own selector so it never collides with a DKIM record your existing provider already publishes.
Optional — merge, never add a second record
If you already have an SPF record, you may merge our sending IPs into it (before the trailing ~all/-all). Never create a second SPF record — two SPF records make SPF invalid. Not required: DMARC passes through DKIM alignment.
Optional TXT record (recommended)
If you have no _dmarc record, adding one improves deliverability and gives you reporting. If you already have one, leave it as it is.