You want to send a newsletter every single time a news will be published? Here you go.

1. (notification_center)[https://github.com/terminal42/contao-notification_center] installed
2. News module enabled
3. Newsletter module enabled

Manual of the Notification Center (German)

Setup "Standard email gateway"

New notification

• Type: News newsletter - Default

New message

• Choose the gateway you added
• Check "Publish message"

Manage languages and add new language

• Select a language and activate "Fallback"
• Simple Tokens:
• ##news_*##
• ##news_archive_*##
• ##news_headline##
• ##news_teaser##
• ##news_text## (content elements)
• ##news_url##

• Add new channel

• Add news archive and enable newsletter in the setting
• Choose the newsletter channel and the notification
• Write a new article and do not publish it by check "Publish item"
• Save and close
• In the news overview click on the envelope icon
• A message shows up saying "Newsletter sent successfully!"