# TCP 110, 995: POP3(S)

> In computing, the Post Office Protocol is an application-layer Internet standard protocol used by e-mail clients to retrieve e-mail from a mail server. POP version 3 is the version in common use.
>
> \-- [*Wikipedia*](https://en.wikipedia.org/wiki/Post_Office_Protocol)

## Related

[SMTP and POP3 commands](https://www.suburbancomputer.com/tips_email.htm)

## General

Connect

```bash
nc -nv <ip> 110
```

or

```bash
telnet <ip> 110
```

```bash
USER user@<ip>
PASS password
```

List all emails

```bash
list
```

Retrieve email number 5, for example

```bash
retr 5
```

Guess users

```bash
nmap -sV --script=pop3-brute <ip>
```

```bash
nmap -p 110 --script pop3-brute --script-args userdb=<usernames-file>,passdb=<passwords-file> <ip>
```

### Nmap scripts

* pop3-brute.nse
* pop3-capabilities.nse
* pop3-ntlm-info.nse


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