Port 25 of telnetpostfix server on other PCs failed!

Port 25 of telnetpostfix server on other PCs failed! -- Linux Enterprise Application-Linux server application information. For details, refer to the following section. Server Environment: FC5, postfix2.2.8-1.2, ip: 192.168.1.199
After the configuration is complete, telnet 192.168.1.199 25 on the local machine, prompting that the connection is successful, but telnet 192.168.1.199 25 on other PCs in the LAN prompts that the connection fails.
After the iptables-a input-p tcp -- dport 25-j ACCEPT command is added to the iptables table
It is best to disable the firewall.

Ask everyone!