This is a simple PHP script that automatically summarizes all incoming emails and prepends the summary to the email content. The script utilizes the MTA-Hook feature provided by Stalwart Mail Servers.
Stalwart Mail Server provides a handy tool, MTA-Hook, that enables the processing of email headers and contents through simple HTTP protocol. With this, we can parse the incoming email content, send it to AI for a summary, then prepend the summary to the content and return it to the mail server.
Below is a screenshot of what it looks like. You can customize the codes and the prompt however you like to fit your needs.
Put the .php file behind a webserver, fill in your API key, plug in the URL into Stalwart MTA-Hooks settings, and enjoy.
Make sure the hook is selected to run on the DATA stage.
By default it uses gpt-4o-mini for higher speed and lower cost. You can however change it to other models or providers easily.