All ports

Port174/TCP

mailq

Port

174

Protocol

TCP

Category

Well-Known

Service

mailq

What is port 174?

Port 174/TCP is a Well-Known port, assigned by IANA for widely recognized services. It is associated with the mailq service.

MAILQ

Useful commands

nmapnmap -p 174 -sV example.com
netcatnc -zv example.com 174
curlcurl -v http://example.com:174/
telnettelnet example.com 174
bash(echo > /dev/tcp/example.com/174) 2>/dev/null

Firewall commands

UFWAllow
sudo ufw allow 174/tcp
Deny
sudo ufw deny 174/tcp
iptablesAllow
sudo iptables -A INPUT -p tcp --dport 174 -j ACCEPT
Deny
sudo iptables -D INPUT -p tcp --dport 174 -j ACCEPT
firewalldAllow
sudo firewall-cmd --permanent --add-port=174/tcp
WindowsAllow
netsh advfirewall firewall add rule name="Open Port 174" dir=in action=allow protocol=TCP localport=174

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 174/TCP?

Port 174/TCP is associated with the mailq service. MAILQ

Is it safe to expose port 174 to the Internet?

It depends on the service and configuration. Port 174 (mailq) is a Well-Known 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 174 is open?

You can use nmap: `nmap -p 174 -sV example.com`, netcat: `nc -zv example.com 174`, or the bash command: `(echo > /dev/tcp/example.com/174) 2>/dev/null && echo "Open" || echo "Closed"`.

How do I open or close port 174 on my firewall?

On Linux with UFW: `sudo ufw allow 174/tcp` (open) or `sudo ufw deny 174/tcp` (close). With iptables: `sudo iptables -A INPUT -p tcp --dport 174 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 174" dir=in action=allow protocol=TCP localport=174`.

What applications and services use port 174?

Port 174/TCP is used by the mailq service. Specific uses depend on the software and configuration. Check our related tools section for more information.