Setting up your email sending domain

Before Telnyx can send email for you, you need to prove you own the domain you send from and configure it so inbox providers trust your mail. You do that by adding a few DNS records. This guide shows you how to add a sending domain, fetch its records, publish them at your DNS provider, verify the domain, and understand what each record does.

Email is currently managed through the Telnyx API, so this guide uses curl. You will also need access to your DNS provider (usually your domain registrar or web host) to add records.

Step 1: Add your domain

Most senders use a subdomain such as mail.yourcompany.com rather than the root domain. A subdomain keeps your sending reputation separate from your regular corporate mail and is the recommended approach. Add it:

curl -X POST https://api.telnyx.com/v2/email_domains \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"domain": "mail.yourcompany.com"}'

The response contains the domain id and a status of pending. Note the id — you use it in the next steps.

Step 2: Fetch your DNS records

Ask Telnyx for the records to publish:

curl https://api.telnyx.com/v2/email_domains/{domain_id}/dns_records \
  -H "Authorization: Bearer YOUR_API_KEY"

Each record in the response has three things you care about:

Host (also called name or record name) — where the record goes, for example mail.yourcompany.com or telnyx1._domainkey.mail.yourcompany.com.
Value — the exact content to paste in.
Required — whether the record is mandatory for verification.

You will receive several record types. For a send-only domain, ownership and DKIM are required for verification. MX is required only when inbound email is enabled for the domain. SPF and DMARC are optional but strongly recommended for good deliverability. Check the per-record results from the verify response to see which requirements apply.

Step 3: Add the records at your DNS provider

Sign in to wherever your domain's DNS is managed and add each record exactly as Telnyx provided it. The general process is the same everywhere:

Choose the record type (TXT or MX) shown by Telnyx.
Paste the host into the name field.
Paste the value into the value/content field.
For MX records, set the priority if your provider asks for one.
Save.

Notes for common providers:


Provider	What to watch for
GoDaddy	Enter only the subdomain part in the Host field (for example `mail`, not the full `mail.yourcompany.com`). GoDaddy appends your domain automatically.
Cloudflare	Set TXT and MX records to DNS only (grey cloud), not proxied. Proxying does not apply to mail records.
Namecheap	Use the Advanced DNS tab. Enter the host without the domain suffix, and use `@` for the root.
Route 53 / Google Domains	Enter the fully-qualified host. If the console splits long TXT values into quoted chunks, that is fine — just do not add extra spaces.

The single most common mistake is adding the domain twice, which produces a host like mail.yourcompany.com.yourcompany.com. Some providers want just the subdomain (mail) and add the rest for you; others want the full host. When in doubt, add the record and then look up what actually got published before verifying.

Step 4: Verify your domain

Once the records are saved, ask Telnyx to check them:

curl -X POST https://api.telnyx.com/v2/email_domains/{domain_id}/verify \
  -H "Authorization: Bearer YOUR_API_KEY"

If everything matches, the domain status becomes verified and you can send. If it does not pass yet, the response shows the status of each individual record so you can see which one still needs attention. DNS changes are not instant — if a record was just added, wait a little and run verify again. See Troubleshooting email domain verification if it keeps failing.

What each record does

You do not need to be a DNS expert, but a little context helps you set things up correctly and troubleshoot later.


Record	Type	What it does
Ownership	TXT	A unique verification string that proves to Telnyx you control the domain. Required.
SPF	TXT	Sender Policy Framework. Lists which servers are allowed to send mail for your domain, so receivers can reject forgeries. Recommended.
DKIM	TXT	DomainKeys Identified Mail. Publishes a public key so receivers can confirm each message was cryptographically signed by you and not altered in transit. Required.
DMARC	TXT	Tells receivers what to do with mail that fails SPF or DKIM, and where to send reports. Increasingly expected by Gmail and Yahoo. Recommended.
MX	MX	Mail Exchange. Routes inbound mail to Telnyx when inbound email is enabled. Required only for an inbound-enabled domain; it is not required for a send-only domain.

Together, SPF, DKIM, and DMARC are how modern inbox providers decide whether to trust your mail. Publishing all of them — and keeping them in place — is the single biggest thing you can do for deliverability.

Keep your records in place

Verification is not a one-time event. Telnyx periodically checks required DNS records. If ownership or DKIM later stops matching — or MX stops matching while inbound email is enabled — the domain can become degraded, and sending is rejected until the required records are restored. SPF or DMARC drift does not degrade the domain or block sending, although incorrect optional records can hurt deliverability. If a domain that used to work suddenly stops, check its required records first.