– you now have a fully functional SMTP load balancer that health-checks your MTAs and distributes connections based on who is least busy.
The application itself maintains a list of MTA endpoints and randomly selects one per message. Libraries like smtp-pool (Node.js) or aiosmtplib (Python with round-robin) implement this. smtp load balancing
frontend smtp_in bind :25 mode tcp default_backend smtp_servers – you now have a fully functional SMTP
Let's build a production-grade SMTP load balancer using (Layer 4) and a pool of Postfix servers on Ubuntu 22.04. smtp load balancing
SMTP load balancing typically involves the following components: