安装sendmail

yum -y install sendmail mailx

2
开启服务器

systemctl start sendmail

查看状态

systemctl start sendmail

3
发送163邮箱测试

echo ‘This is test mail’ | mail -s ‘test’ **@qq.com
以163 为发件箱
#configuration account message that is send email

set from=**@163.com
set smtp=smtp.163.com
set smtp-auth-user=**@163.com
set smtp-auth-password=** (这个是授权码登陆163邮箱设置 IMTP/SMTP 获得)
set smtp-auth=login

以qq为收件箱
在qq邮箱中把发件箱的这个账户加入到白名单

发件为163邮箱 从163邮箱中获取授权码 因为在Linux配置的时候要的密码是u授权码而不是密码
https://www.cnblogs.com/tugeler/p/6620150.html