All ports

Port2004/TCP

mailbox

Port

2004

Protocol

TCP

Category

Registered

Service

mailbox

What is port 2004?

Port 2004/TCP is a Registered port, registered with IANA for specific applications. It is associated with the mailbox service.

Useful commands

nmapnmap -p 2004 -sV example.com
netcatnc -zv example.com 2004
curlcurl -v http://example.com:2004/
telnettelnet example.com 2004
bash(echo > /dev/tcp/example.com/2004) 2>/dev/null

Firewall commands

UFWAllow
sudo ufw allow 2004/tcp
Deny
sudo ufw deny 2004/tcp
iptablesAllow
sudo iptables -A INPUT -p tcp --dport 2004 -j ACCEPT
Deny
sudo iptables -D INPUT -p tcp --dport 2004 -j ACCEPT
firewalldAllow
sudo firewall-cmd --permanent --add-port=2004/tcp
WindowsAllow
netsh advfirewall firewall add rule name="Open Port 2004" dir=in action=allow protocol=TCP localport=2004

Security Risks

  • Open relay used for spam
  • Email spoofing
  • Brute force attacks against email accounts
  • Information disclosure in email headers

Frequently Asked Questions

What service runs on port 2004/TCP?

Port 2004/TCP is associated with the mailbox service. No detailed description is available in the IANA registry.

Is it safe to expose port 2004 to the Internet?

It depends on the service and configuration. Port 2004 (mailbox) is a Registered port. If you need to expose it, keep the service updated, use strong authentication, and configure a firewall. It's always recommended to restrict access by IP when possible.

How do I check if port 2004 is open?

You can use nmap: `nmap -p 2004 -sV example.com`, netcat: `nc -zv example.com 2004`, or the bash command: `(echo > /dev/tcp/example.com/2004) 2>/dev/null && echo "Open" || echo "Closed"`.

How do I open or close port 2004 on my firewall?

On Linux with UFW: `sudo ufw allow 2004/tcp` (open) or `sudo ufw deny 2004/tcp` (close). With iptables: `sudo iptables -A INPUT -p tcp --dport 2004 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 2004" dir=in action=allow protocol=TCP localport=2004`.

What applications and services use port 2004?

Port 2004/TCP is used by the mailbox service. Specific uses depend on the software and configuration. Check our related tools section for more information.

Related ports