[root@db ~]# mkdir .certs
向163邮箱申请证书
[root@db ~]# echo -n | openssl s_client -connect smtp.163.com:465 | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' > .certs/163.crt
[root@db ~]# certutil -A -n "GeoTrust SSL CA" -t "C,," -d ~/.certs -i ~/.certs/163.crt
[root@db ~]# certutil -A -n "GeoTrust Global CA" -t "C,," -d ~/.certs -i ~/.certs/163.crt
列出目录下的证书
[root@db ~]# certutil -L -d ~/.certs/
[root@db ~]# cd .certs/
标记证书
[root@db .certs]# certutil -A -n "GeoTrust SSL CA - G3" -t "Pu,Pu,Pu" -d ./ -i 163.crt