我似乎无法在 CentOS 6.3 专用服务器上打开端口 25。
telnet localhost 25
工作正常，但是在远程尝试时
telnet mydomain.com 25
Connecting To mydomain.com...Could not open connection to the host, on port 25: Connect failed
这是我的 /etc/sysconfig/iptables 的样子：
# Generated by iptables-save v1.4.7 on Tue Dec 11 20:24:48 2012
*raw
:PREROUTING ACCEPT [1239:156878]
:OUTPUT ACCEPT [1017:172599]
COMMIT
# Completed on Tue Dec 11 20:24:48 2012
# Generated by iptables-save v1.4.7 on Tue Dec 11 20:24:48 2012
*nat
:PREROUTING ACCEPT [139:41210]
:INPUT ACCEPT [12:976]
:OUTPUT ACCEPT [91:14636]
:POSTROUTING ACCEPT [91:14636] …