It can be handy to set up email notifications for activities on your Nextcloud installation.
You have to set up your own email address before you can do this (so Nextcloud knows where to send the emails). Click on your username at the top left of the screen and choose Personal. You’ll see a box for your email, just fill it in and press enter.
You can this when you are signed in as an admin by visiting http://<your nextcloudserver>/index.php/settings/admin/additional or clicking Admin in the dropdown menu at the top right of the Nextcloud screen where your username is shown and then on Addtional settings near the bottom of the menu on the left hand side.
Once there you’ll see some empty boxes waiting for your settings.
This is how to fill them in to use your gmail or G Suite account
To check it is working click on the button.
Sending… will appear to the right of the button and be replaced with when it has worked.
If it fails the error message will help show what went wrong.
This what my screen looks like with the right settings.
I was inspired to write this post after following this excellent guidance on getting a Raspberry Pi 3 Nextcloud Box running on Ubuntu Core.