Configure Jenkins to send gmail: What am I missing?

Question

Trying to have Jenkins send an email to a Gmail account upon every build. I get:

Failed to send out e-mail

com.sun.mail.smtp.SMTPSendFailedException: 530-5.5.1 Authentication Required. Learn more at 530 5.5.1 https://support.google.com/mail/?p=WantAuthError 9sm5733284oij.25 - gsm

Here's what I tried so far:

Made the gmail account accept emails from less secure apps

Generated an application password from gmail and used it in my Jenkins configuration - got the same error with and without the app password

Looked at at least a dozen answers (yeah) and all the screens showing the Jenkins gmail config look the same as mine

telnet smpt.gmail.com 465 responds as connected

My Jenkins install is localhost using this URL: http://192.168.0.1:8080/ My system admin email address exists and is entered in Jenkins

I've tried filling in the section on Extended E-mail notification and removing the entries - no difference

Turned off Windows Defender, thinking, just maybe???

Also tried to configure Outlook/Hotmail using those smpt parms but that gave different errors

Don't know if this matters but I have that 'It appears that your reverse proxy set up is broken' and I don't recall setting up a reverse proxy!

Any help would be greatly appreciated!

Set up Jenkins email notification as shown below:

Answer 1

To resolve this, create & use app passwords with 2-step verification turned on.

A less secure method is to allow less secure apps without 2-step verification.