How to send emails from a custom domain purchased in Google Domains

Steps to send emails from your own custom domain purchased in Google Domains without G Suite or after getting the following error (email bouncing back):

Message not delivered: You're sending this from a different address or alias using the 'Send mail as' feature. The settings for your 'Send mail as' account are misconfigured or out of date. Check those settings and try resending.

Go to Google Domains

1. Get a domain: example.com
2. Activate email forwarding:

   • hi@example.com → youremail@gmail.com

Go to your Google account

1. Go to "Security" and activate 2-Step Verification
2. Go to "Security" and add app passwords:
   • Select app: 'Other (Custom name)'
   • Write the name of the domain, e.g. example.com
3. Copy the 16-character password generated

Go to your Gmail account

1. Click on settings and go to "Accounts and Import"
2. Go to "Send mail as" and click on "Add another email address"
3. A new yellowish window will open:
   • Name: Your name
   • Email address: hi@example.com
   • "Treat as an alias" should be activated
4. Next step:
   • SMTP Server: smtp.gmail.com
   • Port: 465
   • User Name: youremail@gmail.com
   • Password: paste the 16-character password
   • "Secured connection using SSL" should be activated
5. Add account