Responsible Mail Server on VPS — Deliverability Basics

DNS & identity

• SPF to authorize sending hosts.
• DKIM signing; DMARC policy/reporting.
• Reverse DNS aligned with sending domain.

Transport & reputation

Enforce TLS, throttle bulk mail, monitor bounces/complaints, and warm up IPs if needed.

Alternatives

For bulk/critical mail, consider reputable SMTP providers integrated with your VPS apps.