WordPress mail error
WordPress wp_mail not sending.
This error usually means the failure happened before inbox delivery: WordPress called `wp_mail()`, PHPMailer selected a transport, and the host or SMTP path rejected the handoff.
Failure-stage evidence
| Evidence | Likely stage | First check |
|---|---|---|
| `wp_mail_failed` appears | WordPress to PHPMailer handoff | Capture the full error data, not just the form success message. |
| `Could not instantiate mail function` | PHP mail transport | Assume host PHP mail is disabled or unreliable; test authenticated SMTP. |
| `SMTP connect() failed` | SMTP connection | Check host, port, TLS/SSL, DNS, and hosting outbound SMTP rules. |
| No SMTP plugin/provider configured | Default WordPress mail | Install one SMTP path only, then run a plain `wp_mail()` test. |
What not to change yet
- Do not change MX records; MX controls receiving mail, not WordPress sending.
- Do not install multiple SMTP plugins at once.
- Do not debug Contact Form 7 or WooCommerce before a plain `wp_mail()` test.