v0.1.0-alpha.2

Changed

• The sender domain's status needs the scope domains:read (or domains:manage), which a test key may have too; the
  settings page, README and readme.txt name it instead of domains:manage.
• On the Postilio PHP SDK at commit 3e671fb84b7b5ebf8f91d06f445f1dcb22fd9347: a test email's timeline knows the
  reason async_bounce, a bounce reported after delivery.

v0.1.0-alpha.1

First version, on the Postilio PHP SDK at commit 8d012a04d008d3dd94b1f2ac488e1d1139503097 (0.1.0-alpha.1, not tagged
yet).

Added

• wp_mail() through the Postilio API, by the pre_wp_mail filter: every plug-in that sends with wp_mail() sends
  through Postilio. The arguments are read as WordPress reads them: recipients in every form, headers as a string or an
  array, From, Reply-To, Cc, Bcc, Content-Type with its charset, multipart/alternative, the custom headers Postilio
  takes, attachments and embeds (WordPress 6.9+).
• Cc and Bcc with one To address as Postilio sends them; several To addresses with Cc or Bcc are refused
  (cc_bcc_require_single_to).
• More than 50 recipients, or more than 25 MB as size times recipients, split into several requests, each with an
  Idempotency-Key from the site, the request and the hour, so a retry never sends twice.
• No fallback to PHP's mail(): a failure returns false and fires wp_mail_failed with the Postilio error code,
  status and trace id; wp_mail_succeeded on success. A line in the PHP error log, without the key, recipients or
  content.
• Settings → Postilio: the API key (the POSTILIO_API_KEY constant in wp-config.php, or a field stored without
  autoload and never shown again), the sender (forced by default), a status line (key, mode, sender domain; one cached
  call), and a test email that shows Postilio's answer.
• A PSR-18 client over the WordPress HTTP API, so the site's proxy and TLS settings apply; the SDK and its
  dependencies bundled with their namespaces prefixed.
• English, and a Dutch (nl_NL) translation.
• WordPress 6.4 or later, PHP 8.2 or later. GPL-2.0-or-later.