node-red-node-email does not fallback to IPv4 if IPv6 connection fails

Which node are you reporting and issue on?

node-red-node-email

What are the steps to reproduce?

Configure an outgoing email using smtp.gmail.com, but running on a IPv4 only network (for example, wifi router or computer without IPv6 enabled). Because smtp.gmail.com answers with a AAAA record first, and that's the one used, the connection will fail.

What happens?

Error: connect EHOSTUNREACH 2607:f8b0:4002:c0f::6d:465 - Local (:::49175)
at internalConnect (node:net:1110:16)
at defaultTriggerAsyncIdScope (node:internal/async_hooks:472:18)
at node:net:1356:9
at process.processTicksAndRejections (node:internal/process/task_queues:84:11)

What did you expect to happen?

After IPv6 connection fails, try the next DNS record which would be an IPv4 address, and then it would succeed. I know this is possible because I was able to patch nodemailer to skip AAAA records. It may however be not as simple to add an actual retry mechanism to the logic.

Environment

• Node-RED version:4.1.2
• Node.js version: 25.2.1
• npm version: n/a
• Platform/OS: mac/macos/brew
• Browser: firefox

Start at the node-red-node-email entry point and trace how the SMTP connection handles DNS results. Reproduce the problem with smtp.gmail.com on an IPv4-only network, then verify that an IPv6 connection failure proceeds to an IPv4 address and the email sends successfully.