一、安装mailx邮件客户端：
yum install mailx -y

二、修改/etc/mail.rc配置文件：

set ssl-verify=ignore
set nss-config-dir=/root/.certs
set from=abc@qq.com
set smtp=smtps://smtp.qq.com:465
set smtp-auth-user=abc@qq.com
set smtp-auth-password=qq邮箱授权码
set smpt-auth=login

三、配置证书：
mkdir -p /root/.certs/
echo -n | openssl s_client -connect smtp.qq.com:465 | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' > ~/.certs/qq.crt
certutil -A -n "GeoTrust SSL CA" -t "C,," -d ~/.certs -i ~/.certs/qq.crt
certutil -A -n "GeoTrust Global CA" -t "C,," -d ~/.certs -i ~/.certs/qq.crt
certutil -L -d /root/.certs

四、在自己的qq邮箱获取授权码：

把生成的授权码复制粘贴到第二步set smtp-auth-password=即可。

五、最后发送邮件：
echo "i am victor chen,hi" | mail -v -s "say hello" xxx@qq.com