The form tries to send a confirmation email through an external SMTP server. The request never reaches the remote host, so the connection expires. WordPress records the failure as a timeout error.
The timeout occurs before authentication finishes. The server aborts the attempt after the preset socket limit is reached. No email is delivered to the recipient or the site administrator.
Typical setups involve a plugin such as WP Mail SMTP that routes CF7 Mail (2) through a third‑party service. If the server cannot open the outbound socket, the plugin returns the same timeout message.
Root causes include network blocks, wrong server details, credential mismatches, DNS problems, or SSL/TLS configuration errors. Each factor stops the handshake at a different stage, but the final symptom remains the same.