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Port 25 (Outbound Email)

Get Real IP blocks outbound connections on port 25 by default. Inbound port 25 is open, so you can receive email without any special setup — the block only affects sending email directly from your IP.

Why it’s blocked by default

Section titled “Why it’s blocked by default”

Port 25 is the port mail servers use to send email to each other. It’s also the port most heavily abused for spam — a compromised or malicious host on an open port 25 can blast spam across the internet in minutes.

Because Get Real IP gives you a dedicated static IP, the reputation of that IP matters — to you and to us. If an IP starts sending spam, it lands on blocklists, and a blocklisted IP is useless for legitimate mail. Blocking outbound port 25 by default:

  • Protects your IP’s reputation — an unattended or misconfigured host can’t accidentally get your address blocklisted.
  • Protects the shared address space — keeps our IP ranges clean so every customer’s mail is trusted.
  • Prevents abuse — a compromised device behind your tunnel can’t be used to relay spam.

This is a standard practice among hosting and network providers for the same reasons.

Requesting outbound port 25

Section titled “Requesting outbound port 25”

If you run a legitimate mail server and need to send email directly from your IP, opening port 25 is a low-friction request — just contact us and let us know. There’s no extra charge.

Include:

  • The IP address (or tunnel) you want unblocked
  • A brief note on what you’re running (e.g. “Postfix for my personal domain”)

We’ll enable outbound port 25 for that address. Once it’s open, make sure you’ve got the basics in place so your mail is trusted — a matching PTR record, and SPF/DKIM/DMARC on your domain.

Alternatives to direct port 25

Section titled “Alternatives to direct port 25”

You don’t strictly need outbound port 25 open to send email. Many self-hosters relay outbound mail through a smart host / relay service (which listens on submission ports 587/465, not 25). That keeps your setup simple and sidesteps port 25 entirely — worth considering if you’d rather not manage direct-to-MX delivery and its reputation requirements.