Notify smtp has stopped working

In the past my notifications by smtp thru gmail worked fine. I only recently saw error messages that said it was not connecting.
I did a search to find a fix and found mention that gmail has added to security requirements. I was using gmail, so I switched to one of my two accounts. That did not work either. Is there somewhere I can learn how to get smtp working again? Or a way to debug my problem? Thank you.
BTW, I was using port 465 because that works with my Thunderbird mail program. After the problem, I tried port 587 as well, but no joy. Thanks, Doug

Thats my config. Pretty straight forward.

I created a separate gmail account for HA notifications, this way they show up as from homeassistnat and I can give them a picture for further ease of identification.

I also setup a 3rd party app password which is the password used in the !secret.

So …

sender: [email protected]
username: [email protected]
password: gmail generated 3rd party password
recepient: my normal gmail

Something to try: My smtp config used to use the default ‘notify’ name. Under the new version of HA it appears that this overlaps with some existing default notification service. Make sure to give it a unique name such as gmailnotify. This was impossible to track down but finally figured it out.