1.安裝mailx
yum -y install mailx
2.配置mail
vim /etc/mail.rc
set from=xxxxxx@qq.com
set smtp=smtps://smtp.qq.com:465
set smtp-auth-user=xxxxxx@qq.com
set smtp-auth-password=你的 QQ 郵箱授權碼
set smtp-auth=login
#set smtp-use-starttls 這里是不需要配置的，很多地方沒說明，配置了反而會驗證失敗，所以我注釋掉；
set ssl-verify=ignore
set nss-config-dir=/root/.certs
3.配置QQ郵箱的SSL證書
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
為了防止出現前文所說的發送郵件警告提示，還需要進入郵箱 SSL 證書存放目錄 /root/.certs 里執行如下命令：
certutil -A -n "GeoTrust SSL CA - G3" -t "Pu,Pu,Pu" -d ./ -i qq.crt
返回如下提示即可：
**Notice: Trust flag u is set automatically if the private key is present.**
4.通過命令行發送測試郵件
mailx -s "郵箱測試" xxxx@qq.com < message_file.txt