Before you can send emails from Appcues Workflows, your sending domain must be verified and your senders must be confirmed. This guide covers the most common issues that occur during domain setup and sender configuration.

For general email delivery and queue issues, see Troubleshoot email workflow issues.

Domain verification stuck on "Pending"

You added all four CNAME records to your DNS, but the domain status in Settings > Emails > Senders still shows Pending.

Check your CNAME records

1. Open a DNS lookup tool like MXToolbox DNS Lookup or run dig CNAME in your terminal.
2. Verify that all four CNAME records from the Appcues email senders page are present and point to the correct values.
3. Confirm there are no typos — a trailing dot, extra space, or wrong subdomain will cause verification to fail silently.

DNS changes can take up to 48 hours to propagate, depending on your DNS provider's TTL settings. If you just added the records, wait at least a few hours before troubleshooting further.

Check your SPF record

A missing or misconfigured SPF record is the most common reason domain verification stays in a pending state even after CNAME records are added.

The SPF record needs to be added to your Appcues sending subdomain (for example, apc.), not necessarily your root domain.

1. Look up TXT records for your Appcues sending subdomain (for example, using MXToolbox DNS Lookup and querying apc.).
2. Confirm a TXT record exists with the value v=spf1 include:mailgun.org ~all.

If it's missing, add a TXT record to your DNS:

• Host/Name: apc (so the full hostname is apc.)
• Value: v=spf1 include:mailgun.org ~all

Important: DNS allows only one SPF TXT record per hostname. If a record already exists for this subdomain, merge include:mailgun.org into it rather than creating a second one.

Refresh and wait

After confirming your CNAME and SPF records are correct:

1. Click Refresh status on the email senders page in Appcues.
2. Allow up to 48 business hours for the Appcues team to complete verification on their end.

The Refresh status button triggers a DNS check within Appcues. There is no way to force faster propagation on the DNS side — propagation depends on your provider's TTL configuration. If you've waited more than 48 business hours and all records look correct, contact support@appcues.com with your Account ID and the domain in question.

Tracking domain SSL errors (HTTP links or ERR_CERT_COMMON_NAME_INVALID)

When a recipient clicks a link in an Appcues email, the link passes through a tracking domain (formatted as t.apc.). If the SSL certificate for that domain isn't provisioned correctly, you'll see one of two symptoms:

• Browser security warning — Chrome shows NET::ERR_CERT_COMMON_NAME_INVALID, meaning the certificate served for the tracking domain doesn't match its hostname.
• HTTP tracking links — Links in the email use http:// instead of https://, meaning there's no certificate at all.

Both are the same root cause: SSL wasn't provisioned for the tracking domain.

Why this happens

Appcues provisions SSL certificates for tracking domains automatically as part of domain verification. This can fail if:

• The tracking domain CNAME is missing or misconfigured. It's one of the four records provided during domain setup. Without it, the certificate can't be issued.
• The certificate hasn't been provisioned yet. If domain verification was just completed, the certificate may still be in progress — allow up to 24 hours.
• A DNS change invalidated the certificate. A domain migration or record update on your side can break an existing certificate.

How to fix it

This requires action from Appcues Support — there is no customer-facing fix. Contact support@appcues.com with:

• Your Account ID
• The full tracking domain hostname (e.g., t.apc.your-domain.com)
• The browser error message or an example HTTP tracking URL from the email

Support will generate an SSL certificate and enable HTTPS for your tracking domain on the backend.

Wanting to send from a different domain

Appcues currently supports only one sending domain per account. If your account is already verified with one domain (for example, @m.example.com), you cannot add senders with a different domain (for example, @example.com) without replacing the existing one.

If you need to switch to a different sending domain, contact support@appcues.com. Be aware that switching requires:

• Updating DNS records for the new domain
• Reconfiguring all existing senders to use the new domain
• Updating any live Workflow email content that references the old sender addresses

If it's still not working

Collect the following before contacting support@appcues.com:

• Account ID — found in Settings > Account.
• Domain — the custom domain or subdomain you're trying to verify.
• DNS records — a screenshot or export from your DNS provider showing the CNAME and SPF records.
• Error details — browser error message, screenshot of the confirmation failure, or the full tracking URL that's misbehaving.
• Timeline — when you added the DNS records and how long they've been in place.