TCP vs SMTP

The internet's reliable old workhorse meets the ancient, reliable backbone of email that somehow still works despite being older than most developers. Here's our take.

TCP

Nice Pick

The internet's reliable old workhorse. It'll get your data there, but don't expect it to be fast or flashy.

Pros

• Guaranteed data delivery with error-checking and retransmission
• Maintains packet order for seamless application communication
• Built-in flow control prevents overwhelming slow receivers

Cons

• Connection setup overhead adds latency compared to UDP
• Congestion control can throttle performance in high-traffic networks

SMTP

The ancient, reliable backbone of email that somehow still works despite being older than most developers.

Pros

• Universally supported across all email systems
• Simple text-based protocol makes debugging straightforward
• Reliable for message transmission with built-in error handling

Cons

• No built-in encryption (requires TLS/SSL add-ons)
• Vulnerable to spam and spoofing without additional security layers

The Verdict

Use TCP if: You want guaranteed data delivery with error-checking and retransmission and can live with connection setup overhead adds latency compared to udp.

Use SMTP if: You prioritize universally supported across all email systems over what TCP offers.

The Bottom Line

TCP wins

The internet's reliable old workhorse. It'll get your data there, but don't expect it to be fast or flashy.