Configuring SMTP server for notifications - compatible email services?

[SteveJY]

I'm in the quick setup trying to configure SMTP email notifications for my TS-431P3 NAS.

Gmail doesn't work - it just gives me an error saying "Sign in with Google temporarily disabled for this app"

I've tried some things I saw suggested - turning on 2FA, turning on allow less secure apps, creating an app password, entering custom settings rather than choosing the Gmail option, but nothing has worked.

I noticed that Yahoo email was also listed as an email account option, so I opened a Yahoo mail account just for sending the notifications. The instructions say to "Allow apps that use less secure sign in" in Yahoo, but this option no longer seems to be offered in the Yahoo account security settings. I tried entering the Yahoo SMTP details as a custom account, but that didn't work either.

Can anyone suggest a free email provider that will just work with the NAS without all this difficulty?

[Mousetick]

Where do you get the error "Sign in with Google temporarily disabled for this app"? Is this message displayed by the NAS or the Google sign-in window?

I just configured a Gmail SMTP service for notifications yesterday and described the procedure in this post there in another thread. I had no such issue, and to really make sure, I sent a test email now. Everything works fine. Using QTS 4.5.1.1480.

[lzyla]

I am unable to add ANY email for notification services. I keep being asked for reauthorization no matter how I add it.
Has anybody a working solution for ANY email that works with notificationsa?
Reauthorization in QNAP is not an option - it doesnt even have a browser, and to be honest - how could this even be considered a soution? You need notifications when you cannot access your server - if you can, you do not need emails...