Unrestricted proxy: what "all ports open" means

20 October 2026

An unrestricted proxy is one that lets your connection through on any port, instead of only the handful the seller has chosen to allow. Most proxy networks quietly close everything except web traffic, so a proxy that loads websites fine can still fail the moment your app needs another port, such as the mail ports 25, 465 and 587.

This guide explains which ports usually get closed and why, what "unrestricted" should and should not mean, and how to test a proxy's ports in a couple of minutes. If you are here because your mail app will not connect, what an SMTP proxy is covers that case in detail.

What a port is

Every connection on the internet goes to an address and a port. The address picks the computer, and the port picks the service on it. Web pages use port 443, or 80 without encryption. Mail apps hand over mail on 587 or 465, and mail servers pass mail to each other on 25. Other software uses its own numbers: remote desktop, databases, game servers, file transfer, and many business tools.

A proxy carries your connection to that address and port on your behalf. If the proxy refuses the port, your app never reaches the service, however good the proxy's addresses are.

Which ports most proxies close

Proxy networks share their addresses between many customers. Anything one customer does reflects on an address the next customer will use, so most networks limit what can go through. The usual restrictions are:

Web only. Many networks allow ports 80 and 443 and nothing else. They are selling access to websites, so everything else is closed by default.
Mail ports closed. Even networks that allow other ports usually close 25, 465 and 587. Mail is the traffic most likely to get a shared address onto a blocklist, so closing the mail ports is the simplest way to protect the pool.
Ports open on request. Some sellers open extra ports only for approved customers, on higher plans, or after a review.

None of this is usually written on the sales page. You find out when your app times out.

What "unrestricted" should mean

Sellers use the word loosely, so pin it down before you buy. A proxy that is genuinely unrestricted on ports means:

Every port, not a list. Not "80, 443 and a few more", but any port your app asks for.
On every plan. Not only on the most expensive tier, and not only after a request.
Mail ports included. If a seller says "all ports" but means "all except mail", it is not the same thing.

It does not mean anything goes. Every proxy still has terms of use, and an open port is a tool, not a permission. The X Proxy, for example, is for lawful, permission-based sending only.

Ports are not the only limit

A proxy can be open on ports and still restrict other things, so ask about these too:

Traffic allowance. How many gigabytes a month you can send through it.
Destinations. Some networks refuse certain kinds of website, whatever the port.
Connections at once. Some plans cap how many connections you can hold open together.

How to test a proxy's ports

You do not have to take a seller's word for it. Windows 10 and 11 include curl, which can send a test through a proxy. In PowerShell, type curl.exe rather than curl, because plain curl is a different command there.

You need four things from your proxy's dashboard: the host, the port, your username and your password. Replace them in the commands below.

Test 1: any port

portquiz.net is a public test server that answers on every port. Ask it for a page on an unusual port, through the proxy:

curl.exe -x socks5h://USER:PASS@HOST:PORT http://portquiz.net:2222

If the page comes back with "Port test successful", the proxy let port 2222 through. Try a few other numbers, such as 8080, 3389 or 5432. If any of them hang and then time out, the proxy is closing those ports.

Test 2: the mail ports

Next, connect to a real mail server on port 587:

curl.exe -v -x socks5h://USER:PASS@HOST:PORT smtp://smtp.gmail.com:587

Look for a line starting with 220 in the output. That is the mail server's greeting, and it means port 587 is open through the proxy. Repeat with smtps://smtp.gmail.com:465 for port 465. A timeout means the port is closed somewhere between you and the server. Port 587 blocked? explains how to tell whether the proxy or your own network is the cause.

Test 3: without the proxy

Run the same commands without the -x part. If a port fails without the proxy too, the block is on your own network or computer, not the proxy.

Why open ports matter for email

For mail, port 587 is the one most apps need: it is where your app signs in to your provider and hands over the message. Port 465 does the same job for providers that prefer it. A proxy with those ports closed simply cannot carry a mail app's connection, which is why "do you block SMTP ports?" is the first question to ask any proxy seller. Port 587 vs 465 vs 25 explains which one your app should use.

Port 25 is a special case. It is for mail servers delivering to each other, and many receiving servers refuse mail delivered straight from home internet addresses. Having it open is useful for testing and for some tools, but most people sending from their own accounts never need it.

The X Proxy: every port open

The X Proxy is a rotating residential proxy with every port open:

Every port is open on every plan, including the mail ports 25, 465 and 587.
Real residential addresses, sourced with consent, across 195+ countries, over HTTPS or SOCKS5.
One address for 10 minutes at a time, or a new one on every request. You choose when you buy.
50 GB of traffic a month, and it works with any tool, not just X Mailer.

Run the tests above on it the day you buy. If a port does not answer, tell us.

Common questions

Is an unrestricted proxy the same as an open proxy?

No. An open proxy is one that anyone on the internet can use without signing in, usually by mistake. An unrestricted proxy still needs your username and password, or your own internet address, before it carries anything. "Unrestricted" describes which ports it allows, not who can use it.

Do I need every port open?

Often not. If you only browse, 443 is enough. But if you use mail apps, remote desktop, databases or your own software, a proxy with every port open saves you from finding out the hard way which ports a seller left closed.

Does an open port make my connection less safe?

No. The proxy only passes your connection along. Whether that connection is encrypted depends on your app and the service, not on the port being open.

In short

An unrestricted proxy lets your connection through on any port. Most proxy networks allow only web traffic, and nearly all close the mail ports.
Pin down what a seller means by "unrestricted": every port, on every plan, mail ports included.
Test it yourself with curl.exe and portquiz.net, then with a real mail server on 587.
The X Proxy has every port open on every plan, including 25, 465 and 587.