Configure Elastic Email in Regal Send

Updated September 20, 2026

Use this guide to configure Elastic Email in Regal Send for WordPress transactional email. Regal Send uses the Elastic Email REST API v4, stores the API key in encrypted form and submits each prepared WordPress message to the transactional email endpoint. You need an Elastic Email account, a verified sender or domain, and an API key with SendHttp access.

Before you configure Elastic Email in Regal Send#

  • Create or access an Elastic Email account.
  • Verify the From address or sending domain that WordPress will use.
  • Decide whether Regal Send should force one From Email for all site messages.
  • Make sure WordPress can make outbound HTTPS requests to api.elasticemail.com.

A successful API response means Elastic Email accepted the transactional request. It does not prove delivery to the recipient’s inbox.

Verify the sender in Elastic Email#

  1. Sign in to Elastic Email and open the domain or sender verification area.
  2. Add the domain or individual email address you want WordPress to send from.
  3. Complete the DNS or email verification steps shown by Elastic Email.
  4. Wait until Elastic Email reports that the sender is verified.

Regal Send does not make a remote sender-verification request when the settings page loads. Elastic Email remains authoritative and can reject an otherwise valid message when its From address is not verified.

Create a SendHttp API key#

  1. Open Settings and the API key management area in Elastic Email.
  2. Create a new key with a recognisable name such as Regal Send for your website.
  3. Grant the SendHttp access level required by the transactional endpoint.
  4. Avoid unrelated account, contact, campaign or billing permissions.
  5. Copy the key when Elastic Email displays it.

Treat the key like a password. If it is exposed, remove it in Elastic Email, create a replacement and update Regal Send. The Elastic Email REST API v4 documentation lists SendHttp as the access level for transactional email.

Save the API key in Regal Send#

  1. In WordPress, open Regal Send > Settings.
  2. Select Elastic Email.
  3. Paste the API key into the empty API key field.
  4. Set From Email to a verified sender. Enable Force From Email if every plugin should use that address.
  5. Set a suitable From Name and logging mode.
  6. Select Save settings.

The saved key is encrypted and never returned to the browser. Regal Send shows API key saved beside an empty replacement field. Leaving that field blank keeps the saved key. Entering a new key replaces it, while the separate removal option deletes it after settings are saved.

How Regal Send sends through Elastic Email#

Regal Send keeps WordPress and PHPMailer responsible for recipient parsing and message preparation. It then translates To, CC, BCC, Reply-To, From, subject, HTML, plain-text content and readable attachments into Elastic Email’s transactional JSON format.

Attachment content is base64 encoded for the API request. Dangerous transport or authentication headers are not forwarded. The API key is sent only in the X-ElasticEmail-ApiKey request header and is not placed in the JSON body, HTML, logs or provider diagnostics.

Troubleshoot Elastic Email sending#

API key required#

Save an Elastic Email API key before selecting the mailer. If a previously saved key can no longer be decrypted, replace it in Settings.

Elastic Email rejects the API key#

Confirm that the key is active and includes SendHttp access. Replace an expired, deleted or incorrectly copied key. Regal Send maps HTTP 401 and 403 to a safe authentication message without storing Elastic Email’s raw response.

The sender or message is rejected#

Confirm that the final From Email is verified in Elastic Email. Review recipients, subject, message content and attachment size. A caller-supplied From address is preserved unless Force From Email is enabled, so another plugin can supply an unverified sender.

An attachment cannot be read#

Regal Send fails before contacting Elastic Email when a file attachment is missing or unreadable. Restore the source file or remove the attachment from the originating email workflow, then try again.

Elastic Email rate limits the request#

A rate-limited result is marked as retryable. Wait and try again rather than repeatedly submitting the same message immediately. Check the Elastic Email account limits and status if rate limiting continues.

The API accepted the email but it did not arrive#

Check Email Logs for the transaction and message identifiers, then use Elastic Email’s activity or reporting tools. Also check the recipient address, suppression status, bounce information, junk folder and domain authentication.

Remove or rotate the API key#

To rotate a key, enter the replacement and save settings, then revoke the old key in Elastic Email. To disconnect Regal Send, select Remove saved API key and save. Removing the local key does not delete it from the Elastic Email account, so revoke unused keys at the provider as well.

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