安装mailx

yum install mailx -y

修改mail.rc

vim /etc/mail.rc
# 添加如下内容
set from=14503226@qq.com
set smtp=smtp.qq.com
set smtp-auth-user=14503226@qq.com
set smtp-auth-password=邮箱后台生成的授权码
set smtp-auth=login

发送邮件

echo "邮件正文" | mail -s "邮件主题" 14503226@qq.com
echo "邮件正文-测试发送附件" | mail -s "邮件标题" -a file.txt 14503226@qq.com