openssl s_client -connect flateight.com:443 -showcerts

openssl s_client -connect flateight.com:443 -showcerts
CONNECTED(00000003)
depth=2 /C=BE/O=GlobalSign nv-sa/OU=Root CA/CN=GlobalSign Root CA
verify return:1
depth=1 /C=BE/O=GlobalSign nv-sa/CN=GlobalSign Domain Validation CA - G2
verify return:1
depth=0 /C=JP/OU=Domain Control Validated/CN=login.gmocloudpublic.com
verify return:1

SSL-Session:
    Verify return code: 0 (ok)

中間証明書が正しく設定されてない場合

openssl s_client -connect flateight.com:443 -showcerts
CONNECTED(00000003)
depth=0 /C=JP/OU=Domain Control Validated/CN=login.gmocloudpublic.com
verify error:num=20:unable to get local issuer certificate
verify return:1
depth=0 /C=JP/OU=Domain Control Validated/CN=login.gmocloudpublic.com
verify error:num=27:certificate not trusted
verify return:1
depth=0 /C=JP/OU=Domain Control Validated/CN=login.gmocloudpublic.com
verify error:num=21:unable to verify the first certificate
verify return:1

SSL-Session:
    Verify return code: 21 (unable to verify the first certificate)

http://valuessl.net/support/checker.php

https://www.sslshopper.com/ssl-checker.html