How do I fix WordPress email with Layer 9 SMTP?

WordPress often fails silently when using PHP mail. Authenticated SMTP via Layer 9 fixes contact forms, WooCommerce orders, and membership emails.

Plugin setup pattern

Install a trusted SMTP plugin, enter mail.l9s.io, port 587, encryption STARTTLS, and your SMTP username/password.

Send a test email and confirm SPF/DKIM pass on a seed inbox.