$ openssl s_client -starttls smtp -crlf -ssl3 -connect smtp.mail.yahoo.com:587 CONNECTED(00000003) depth=1 C = US, O = DigiCert Inc, OU = www.digicert.com, CN = DigiCert High Assurance CA-3 verify error:num=20:unable to get local issuer certificate verify return:0 --- Certificate chain 0 s:/C=US/ST=CA/L=Sunnyvale/O=Yahoo! Inc./CN=smtp.mail.yahoo.com i:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert High Assurance CA-3 1 s:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert High Assurance CA-3 i:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert High Assurance EV Root CA --- Server certificate -----BEGIN CERTIFICATE----- MIIHITCCBgmgAwIBAgIQBlVSvxlwsqw8Kc8eVV5EKTANBgkqhkiG9w0BAQUFADBm MQswCQYDVQQGEwJVUzEVMBMGA1UEChMMRGlnaUNlcnQgSW5jMRkwFwYDVQQLExB3 d3cuZGlnaWNlcnQuY29tMSUwIwYDVQQDExxEaWdpQ2VydCBIaWdoIEFzc3VyYW5j ZSBDQS0zMB4XDTE0MDYwNTAwMDAwMFoXDTE1MDYyMzEyMDAwMFowYjELMAkGA1UE BhMCVVMxCzAJBgNVBAgTAkNBMRIwEAYDVQQHEwlTdW5ueXZhbGUxFDASBgNVBAoM C1lhaG9vISBJbmMuMRwwGgYDVQQDExNzbXRwLm1haWwueWFob28uY29tMIIBIjAN BgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA339OSxTIuW6NVqKwYHFBbg4/tmEx MYpzohtObPaWgvLTsYdce+WlQFBU5rxaCMUtVsVAGJWs5uQRDVHXRLPnOWe+foqZ 5ItgjYIQc1XeMv6BZEeaF3Bum5ehUyLB3y48cjbWxma1QlkZ8XAK0f9AS7ySWAen o5OXJlMFAqXGtKMAhY46dzSY0wjgdrvgiomFRy0iQKV1DxGsXoXSMEszlUTQoNQ3 WTsiA3O//cdWE06wWeA3/90cb7QkU3KflSoyfi878BQGpPR1L+rLNsqnc8QuucbD z4Q++rxGqgg4QYrOtmZfAn96TXhPWCwKld6FN+f3uV5ITOBFx44M5v1ILQIDAQAB o4IDzTCCA8kwHwYDVR0jBBgwFoAUUOpzidsp+xCPnuUBINTeeZlIg/cwHQYDVR0O BBYEFEhOpSFQjO/QrSNfVwyInZUhyzhsMIICJAYDVR0RBIICGzCCAheCE3NtdHAu bWFpbC55YWhvby5jb22CFnNtdHAubWFpbC55YWhvby5jb20uYXKCFnNtdHAubWFp bC55YWhvby5jb20uYXWCFnNtdHAubWFpbC55YWhvby5jb20uYnKCFnNtdHAubWFp bC55YWhvby5jb20uY26CFnNtdHAubWFpbC55YWhvby5jb20uaGuCFnNtdHAubWFp bC55YWhvby5jb20ubXmCFnNtdHAubWFpbC55YWhvby5jb20ucGiCFnNtdHAubWFp bC55YWhvby5jb20uc2eCFnNtdHAubWFpbC55YWhvby5jb20udHeCFnNtdHAubWFp bC55YWhvby5jb20udm6CFXNtdHAubWFpbC55YWhvby5jby5pZIIVc210cC5tYWls LnlhaG9vLmNvLmlughVzbXRwLm1haWwueWFob28uY28ua3KCFXNtdHAubWFpbC55 YWhvby5jby50aIIVc210cC5tYWlsLnlhaG9vLmNvLnVrghJzbXRwLm1haWwueWFo b28uY2GCEnNtdHAubWFpbC55YWhvby5jboISc210cC5tYWlsLnlhaG9vLmRlghJz bXRwLm1haWwueWFob28uZXOCEnNtdHAubWFpbC55YWhvby5mcoISc210cC5tYWls LnlhaG9vLml0gg9zbXRwLnk3bWFpbC5jb22CFHNtdHAuY29ycmVvLnlhaG9vLmVz MA4GA1UdDwEB/wQEAwIFoDAdBgNVHSUEFjAUBggrBgEFBQcDAQYIKwYBBQUHAwIw YQYDVR0fBFowWDAqoCigJoYkaHR0cDovL2NybDMuZGlnaWNlcnQuY29tL2NhMy1n MjguY3JsMCqgKKAmhiRodHRwOi8vY3JsNC5kaWdpY2VydC5jb20vY2EzLWcyOC5j cmwwQgYDVR0gBDswOTA3BglghkgBhv1sAQEwKjAoBggrBgEFBQcCARYcaHR0cHM6 Ly93d3cuZGlnaWNlcnQuY29tL0NQUzB7BggrBgEFBQcBAQRvMG0wJAYIKwYBBQUH MAGGGGh0dHA6Ly9vY3NwLmRpZ2ljZXJ0LmNvbTBFBggrBgEFBQcwAoY5aHR0cDov L2NhY2VydHMuZGlnaWNlcnQuY29tL0RpZ2lDZXJ0SGlnaEFzc3VyYW5jZUNBLTMu Y3J0MAwGA1UdEwEB/wQCMAAwDQYJKoZIhvcNAQEFBQADggEBABshjUND4hADHGfe cV9XGXcr9h3u7mT5kgdcgGFhcrFAlwkzt0NUCbuN0X8DWHE72Tpb3zRE25CmUUJe ktBbq9PQb4b5/Wt1htAEw0qUs3BsUbqejK9OHJ/11Jn2ek4+SLJuYlijzc7KM3F/ yz7ZTZtKR0PglkXfqbpvWYGabYpfL2FRLoJ7alTLsMJcFxbSLYcAIMxufj7RyTBJ bKgRJl4wmP4+Zc2Q1p59mENY0u5HqVAAOmWc0jNb0/31+tRr5f6EgXxK++7TQOpF 0TOaFsXlzRlpKfmIbzVr2nfwghV5/bRZj96TK3g1OoOz4C8ksK4INHnUdTAqZ18M vHpnJw4= -----END CERTIFICATE----- subject=/C=US/ST=CA/L=Sunnyvale/O=Yahoo! Inc./CN=smtp.mail.yahoo.com issuer=/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert High Assurance CA-3 --- No client certificate CA names sent --- SSL handshake has read 4124 bytes and written 319 bytes --- New, TLSv1/SSLv3, Cipher is ECDHE-RSA-RC4-SHA Server public key is 2048 bit Secure Renegotiation IS supported Compression: NONE Expansion: NONE SSL-Session: Protocol : SSLv3 Cipher : ECDHE-RSA-RC4-SHA Session-ID: 742A7B39AA0852E27294B2B8C33CD9475BAAEFE4F065504D0AF5819B99A7CC53 Session-ID-ctx: Master-Key: 9763FDE49F75C0AD4EF355CF00DE608BFC0B474F7B94BD68240CFB1AE6F749C68D4B9166556E725C1AAD7D46845B8FD1 Key-Arg : None PSK identity: None PSK identity hint: None SRP username: None Start Time: 1413452904 Timeout : 7200 (sec) Verify return code: 20 (unable to get local issuer certificate) --- 250 STARTTLS