Volanea Email Delivery

Volanea Email Delivery hands every wp_mail() call to the Volanea HTTP API, so password
resets, order receipts, form notifications and everything else leave your site
over an authenticated API connection rather than the server’s local mail()
binary.

The plugin does not speak SMTP. It uses Volanea’s HTTPS API, which means there
is no port to unblock and no SMTP password stored on the site.

Never silently dropped

The plugin only takes over a message it can send faithfully. If the API refuses
the message, the key is wrong, the network fails, or the message uses something
the API cannot express, the plugin steps aside and WordPress delivers it the way
it always did. A failed send is never a lost send.

What it handles

• To, Cc, Bcc and Reply-To
• HTML and plain text bodies, including the wp_mail_content_type filter
• Attachments (up to 10 per message)
• Custom headers such as X- headers
• Headers passed as either a string or an array, in any combination
• Recipient lists longer than the API’s 50-address limit, split automatically

Known differences from the default mailer

These are worth reading before you switch a busy site over.

• Cc and Bcc. The Volanea API has no Cc or Bcc field. The plugin gives each
  copied address its own message, which is exactly right for Bcc: the copy
  arrives and no one else can see it. A Cc recipient also receives the message,
  but no visible Cc: header is present on any copy. If you need a real Cc
  header, turn off “Deliver Cc and Bcc recipients as individual copies” and
  those messages will go through the default WordPress mailer instead.
• One message per recipient. A message addressed to several people is sent
  as a separate message to each, so recipients do not see one another.
• Multiple Reply-To addresses. The API accepts one; the first is used.
• Plain-text messages. The API renders a text-only body inside a <pre>
  block, so plain-text email looks a little different from mail() output.
• Hand-built multipart messages. A message that supplies its own MIME
  boundary is passed to the default mailer untouched.
• A 200 response is not delivery. The API accepts the message and delivers
  it afterwards. The recipient may still be skipped for being suppressed,
  unsubscribed or over quota. Skips are recorded in the log and, deliberately,
  are not retried through mail().

Storing the API key more safely

By default the key is stored in the options table. To keep it out of the
database entirely, add this to wp-config.php:

define( 'VOLANEA_EMAIL_DELIVERY_API_KEY', 'your-secret-key' );

The constant wins over anything saved in the admin, and the settings page then
shows the key as read-only and masked.

Filters for developers

• volanea_email_delivery_api_base — change the API base URL, for staging.
• volanea_email_delivery_request_args — adjust the wp_remote_post() arguments.
• volanea_email_delivery_payload — modify the request body before it is sent.

External services

This plugin sends your site’s outgoing email to Volanea, a third-party email
delivery service, so that it can be delivered.

It contacts https://api.volanea.com only when you have saved an API key, and
only at these moments:

• Every time WordPress sends an email while the plugin is configured.
• When you press “Send test email” on the settings screen.

The data sent with each message is: the sender name and address, the recipient
addresses, the subject, the message body, any custom headers set by the code
that sent the mail, and any attachments. No data is transmitted before you
enter an API key.

Volanea’s terms of service: https://volanea.com/legal/terms
Volanea’s privacy policy: https://volanea.com/legal/privacy