Nodemailer “Greeting never received” or “Connection closed unexpectedly” on port 465

Two messages, one cause

On 16.10.2026 we sent with Node.js 22.23 and nodemailer 10.1.1 to port 465 with secure: false on four real servers, with made-up logins:

The difference is only who gives up first. Nodemailer's greeting timeout is 30 seconds by default; Gmail and Zoho closed the silent connection after about 10. Either way, a visitor who pressed Send waited that long for nothing.

Why the connection goes silent

SMTP servers use two ways to encrypt. On port 465 the TLS handshake comes first, before any SMTP text. On port 587 (and 25) the server first sends a plain greeting such as 220 smtp.gmail.com ESMTP, and the client then upgrades the same connection with STARTTLS.

secure: false tells Nodemailer to expect the plain greeting. On port 465 the server is waiting for the client to start TLS, and the client is waiting for the server to say hello. Nobody speaks until a timeout ends it. The opposite mistake, secure: true on 587, fails instantly with “wrong version number”.

// Port 465: TLS from the first byte
nodemailer.createTransport({ host: "smtp.gmail.com", port: 465, secure: true, auth });

// Port 587: plain connection, upgraded with STARTTLS
nodemailer.createTransport({ host: "smtp.gmail.com", port: 587, secure: false, auth });

When the settings are already right

If you use 465 with secure: true and still time out, the connection is probably blocked before it reaches the server. Many cloud hosts restrict outgoing mail ports, port 25 most of all, and some office networks allow only their own mail server. From the same machine, nc -vz smtp.gmail.com 465 tells you in a second whether the port is reachable at all. If it is not, use the port your host allows or the mail provider's HTTP API instead of SMTP.

Do you need SMTP for a contact form?

If the SMTP login exists only so a contact form can email you, you can drop it: a form that posts to Formgong at https://formgong.com/submit has no SMTP host, port or password in your code, and Formgong sends the notification itself. See the HTML guide.