All ports
Port2390/UDP
rsmtpPort
2390
Protocol
UDP
Category
Registered
Service
rsmtp
What is port 2390?
Port 2390/UDP is a Registered port, registered with IANA for specific applications. It is associated with the rsmtp service.
RSMTP
Useful commands
nmapnmap -p 2390 -sV example.comnetcatnc -zv example.com 2390curlcurl -v http://example.com:2390/telnettelnet example.com 2390bash(echo > /dev/udp/example.com/2390) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 2390/udpDeny
sudo ufw deny 2390/udpiptablesAllow
sudo iptables -A INPUT -p udp --dport 2390 -j ACCEPTDeny
sudo iptables -D INPUT -p udp --dport 2390 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=2390/udpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 2390" dir=in action=allow protocol=UDP localport=2390Security 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 2390/UDP?
Port 2390/UDP is associated with the rsmtp service. RSMTP
Is it safe to expose port 2390 to the Internet?
It depends on the service and configuration. Port 2390 (rsmtp) 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 2390 is open?
You can use nmap: `nmap -p 2390 -sV example.com`, netcat: `nc -zv example.com 2390`, or the bash command: `(echo > /dev/udp/example.com/2390) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 2390 on my firewall?
On Linux with UFW: `sudo ufw allow 2390/udp` (open) or `sudo ufw deny 2390/udp` (close). With iptables: `sudo iptables -A INPUT -p udp --dport 2390 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 2390" dir=in action=allow protocol=UDP localport=2390`.
What applications and services use port 2390?
Port 2390/UDP is used by the rsmtp service. Specific uses depend on the software and configuration. Check our related tools section for more information.