How do I let my AI agent send emails without hardcoding SMTP credentials in the code?

I am building an AI agent on a DigitalOcean Droplet that needs to send email notifications when certain conditions are met. The agent uses the DigitalOcean inference platform to make decisions about when to send alerts.

My question is about the email side. I have seen people hardcode SMTP credentials directly in their scripts which feels wrong, especially for a long-running agent. What is the best way to handle SMTP credentials securely, and is there a cleaner way to give an AI agent the ability to send emails without managing raw SMTP connections in the code?