Help Center

What Are Open Ports on a DigitalOcean Droplet?

Quick Answer

Open ports on a DigitalOcean droplet determine what network traffic is allowed in and out. Port 25 (SMTP) is blocked by default to prevent spam. Open-port accounts have key ports like 25 unblocked, letting you run mail servers and services that need them.

Inbound vs outbound ports

Inbound ports control traffic reaching your droplet (like 80/443 for web). Outbound ports control traffic your droplet sends — most importantly port 25 for email. DigitalOcean blocks outbound port 25 on new accounts to prevent spam.

Why open ports matter

If you're running a mail server, you need outbound port 25 open. For other services, you configure inbound rules via your droplet's firewall. Open-port-25 accounts come with SMTP already enabled, removing the main email roadblock.

Managing droplet ports

Use DigitalOcean Cloud Firewalls or the droplet's own firewall (ufw, iptables) to control inbound ports. Outbound port 25 must be unblocked at the account level — which is why pre-opened accounts are valuable for email.