WordPress Proposes Full Unicode Email Address Support

WordPress has long been limited to US‑ASCII email addresses, but the industry now supports full UTF‑8 email addresses via RFC 6530. The core team is proposing to relax the sanitization logic in is_email(), sanitize_email() and antispambot() so that Unicode addresses can be stored and validated. PR #5237 unlocks this capability by adding a new WP_Email_Address class and new functions wp_is_unicode_email() and wp_sanitize_unicode_email(), while a filter restricts the feature to sites whose database uses utf8mb4. The change also requires updating any code that assumes single‑byte emails, such as strlen() or custom validation hooks. WordPress 6.9 already shipped PHPMailer support for sending Unicode addresses, but the user‑account side was missing. The proposal includes a clear audit path for plugins that may break when the new logic is enabled.

The core team is asking for feedback on the implementation and the communication strategy for site owners who may need to migrate to utf8mb4. The change is not a release yet but will be part of a future major update. The impact is primarily on WordPress site owners who use non‑ASCII email addresses.