Smtp Load Balancing 〈VERIFIED - 2026〉

example.com. 300 IN MX 10 mail1.example.com. example.com. 300 IN MX 10 mail2.example.com. example.com. 300 IN MX 20 mail3-backup.example.com.

⚠️ are rarely needed for SMTP – each email is independent. smtp load balancing

defaults mode tcp timeout connect 5s timeout client 60s timeout server 60s log global example