Sending emails doesn't work because of Avast or AVG antivirus

Avast and AVG have released an update that prevents email from being sent from Outlook or Thunderbird. This can be reactivated by following the procedure below:

Open your AVG or Avast settings, it should look like this:

1. Click on "Menu "

2. Click on "Settings "

3. Click on „Protection " → "Main Shields " → scroll down and there click on "Mail Shield " → Uncheck "Test outgoing emails (SMTP) “

That's it, sending emails should work again.

There is a way to disable AVG: Menu > Settings > Basic Protection and click on Email Shield – you need to uncheck it.