前言:
新上一台阿里的云主机，提供web服务，各种环境搭建完成，能够提供服务，没想到在最后的监控环节遇到各种发邮件的坑，这里分享给大家，你是否也遇到这种坑？
网易163免费邮箱相关服务器信息：
一、安装和配置:
1.1、安装
[root@linux-node2 ~]# yum install mailx -y Loaded plugins: fastestmirror, security Setting up Install Process Determining fastest mirrors * base: mirrors.aliyun.com * extras: mirrors.aliyun.com * updates: mirrors.aliyun.com base | 3.7 kB 00:00 epel | 3.2 kB 00:00 epel/primary | 3.2 MB 00:00 epel 12521/12521 extras | 3.4 kB 00:00 icehouse | 2.9 kB 00:00 updates | 3.4 kB 00:00 updates/primary_ | 1.2 MB 00:00 Package mailx-12.4-8.el6_6.x86_64 already installed and latest version Nothing to do
1.2、配置(以163邮箱为例)
首先你的邮箱要支持你的需求，到邮箱里去配置
然后到/etc/mail.rc的配置文件中去添加
set from=admin@163.com smtp=smtp.163.com smtp-auth-user=admin smtp-auth-password=xxxxxx smtp-auth=login
[root@linux-node2 ~]# echo “12345” | mail -v -s “test” admin@163.com
至此应该是没问题，但是就是收不到邮件。得了，开始排错！所有的网络、配置检查完成后，还是收不到邮件，最后检查到端口发现问题！！！
[root@linux-node2 ~]# telnet smtp.163.com 25
Trying 220.181.12.17...
^C
[root@orcherstrator ~]# nc -vz -w 1 smtp.163.com 25
nc: connect to smtp.163.com port 25 (tcp) timed out: Operation now in progress
nc: connect to smtp.163.com port 25 (tcp) timed out: Operation now in progress
nc: connect to smtp.163.com port 25 (tcp) timed out: Operation now in progress
nc: connect to smtp.163.com port 25 (tcp) timed out: Operation now in progress
nc: connect to smtp.163.com port 25 (tcp) timed out: Operation now in progress
nc: connect to smtp.163.com port 25 (tcp) timed out: Operation now in progress
nc: connect to smtp.163.com port 25 (tcp) timed out: Operation now in progress
nc: connect to smtp.163.com port 25 (tcp) timed out: Operation now in progress
原来服务器根本就不能和第三方邮箱建立连接，问题找到，开始处理，一查才知道阿里云服务器把25端口给封了，需要申请解封。好吧！登录管理控制台，开始申请！！！
