Found this: https://serverfault.com/questions/635139/how-to-fix-send-mail-authorization-failed-534-5-7-14
Doesn't look like a problem specific to Node-RED, more of a Gmail security thing.
Found this: https://serverfault.com/questions/635139/how-to-fix-send-mail-authorization-failed-534-5-7-14
Doesn't look like a problem specific to Node-RED, more of a Gmail security thing.