$ openssl s_client -starttls smtp -crlf -ssl3 -connect smtp.posteo.de:587 CONNECTED(00000003) depth=1 C = IL, O = StartCom Ltd., OU = StartCom Certification Authority, CN = StartCom Extended Validation Server CA verify error:num=20:unable to get local issuer certificate verify return:0 --- Certificate chain 0 s:/C=DE/ST=Berlin/L=Berlin/postalCode=10965/street=Methfesselstra\xDFe 38/O=Posteo e.K./CN=www.posteo.de/emailAddress=postmaster@posteo.de/serialNumber=HRA 47592/businessCategory=Private Organization/1.3.6.1.4.1.311.60.2.1.1=Charlottenburg/1.3.6.1.4.1.311.60.2.1.2=Berlin/1.3.6.1.4.1.311.60.2.1.3=DE i:/C=IL/O=StartCom Ltd./OU=StartCom Certification Authority/CN=StartCom Extended Validation Server CA 1 s:/C=IL/O=StartCom Ltd./OU=StartCom Certification Authority/CN=StartCom Extended Validation Server CA i:/C=IL/O=StartCom Ltd./OU=Secure Digital Certificate Signing/CN=StartCom Certification Authority --- Server certificate -----BEGIN CERTIFICATE----- MIIH2TCCBsGgAwIBAgICDEAwDQYJKoZIhvcNAQELBQAwgYExCzAJBgNVBAYTAklM MRYwFAYDVQQKEw1TdGFydENvbSBMdGQuMSkwJwYDVQQLEyBTdGFydENvbSBDZXJ0 aWZpY2F0aW9uIEF1dGhvcml0eTEvMC0GA1UEAxMmU3RhcnRDb20gRXh0ZW5kZWQg VmFsaWRhdGlvbiBTZXJ2ZXIgQ0EwHhcNMTQwNDE2MTMwMzA2WhcNMTYwNDE2MTYy MzA0WjCCATIxCzAJBgNVBAYTAkRFMQ8wDQYDVQQIEwZCZXJsaW4xDzANBgNVBAcT BkJlcmxpbjEOMAwGA1UEERMFMTA5NjUxHDAaBgNVBAkUE01ldGhmZXNzZWxzdHJh 32UgMzgxFDASBgNVBAoTC1Bvc3RlbyBlLksuMRYwFAYDVQQDEw13d3cucG9zdGVv LmRlMSMwIQYJKoZIhvcNAQkBFhRwb3N0bWFzdGVyQHBvc3Rlby5kZTESMBAGA1UE BRMJSFJBIDQ3NTkyMR0wGwYDVQQPExRQcml2YXRlIE9yZ2FuaXphdGlvbjEfMB0G CysGAQQBgjc8AgEBEw5DaGFybG90dGVuYnVyZzEXMBUGCysGAQQBgjc8AgECEwZC ZXJsaW4xEzARBgsrBgEEAYI3PAIBAxMCREUwggEiMA0GCSqGSIb3DQEBAQUAA4IB DwAwggEKAoIBAQCtuMx0JvI0No44Yfjhj83bzimzmk9mJj7pf8vr2fE29KhYCYgS LwRsQBx7LZ35hvUan3jvumbDYOKtiuuEX0lRE6YvFIf55ifp/5jkTxTvuHbfRgfv OeaVHGDGkmhaDYULRwV2zp0xNTj7I2kivrVC9AqU23Sk9y51ORrNUjeNZev+Wu4h cFdgPNf6ZuvwfOVbEOTBFYxO63bAfVvVXOq2MvvRtdmTO/wVEAnMjs2sui6xDT6E rrHTjaFnqyHqRK24RNZlaTgWOtBzw/LUtY/GOi55EYvQWS2W71JVGHDN/m/YyOBp r1ZU6WvVXr0e3zcb7WsyYjMhVA0E8lU1uo1vAgMBAAGjggOlMIIDoTAJBgNVHRME AjAAMAsGA1UdDwQEAwIDqDAdBgNVHSUEFjAUBggrBgEFBQcDAgYIKwYBBQUHAwEw HQYDVR0OBBYEFEGWEO3MkcHhxnjkblz5+vd2rjWBMB8GA1UdIwQYMBaAFKHhnkUl eU0G2QIXkoLVMIlyJRSgMIGbBgNVHREEgZMwgZCCDXd3dy5wb3N0ZW8uZGWCCXBv c3Rlby5kZYILbS5wb3N0ZW8uZGWCD2xpc3RzLnBvc3Rlby5kZYIWYXV0b2Rpc2Nv dmVyLnBvc3Rlby5kZYIObXgwMS5wb3N0ZW8uZGWCDm14MDIucG9zdGVvLmRlgg5t eDAzLnBvc3Rlby5kZYIObXgwNC5wb3N0ZW8uZGUwggGbBgNVHSAEggGSMIIBjjAL BgkrBgEEAYG1NwIwDQYLKwYBBAGBtTcBAQEwggFuBgsrBgEEAYG1NwECAzCCAV0w LgYIKwYBBQUHAgEWImh0dHA6Ly93d3cuc3RhcnRzc2wuY29tL3BvbGljeS5wZGYw MAYIKwYBBQUHAgEWJGh0dHA6Ly93d3cuc3RhcnRzc2wuY29tL2V4dGVuZGVkLnBk ZjCB+AYIKwYBBQUHAgIwgeswJxYgU3RhcnRDb20gQ2VydGlmaWNhdGlvbiBBdXRo b3JpdHkwAwIBARqBv1RoaXMgY2VydGlmaWNhdGUgd2FzIGlzc3VlZCBhY2NvcmRp bmcgdG8gdGhlIEV4dGVuZGVkIFZhbGlkYXRpb24gcmVxdWlyZW1lbnRzIG9mIHRo ZSBTdGFydENvbSBDQSBwb2xpY3ksIHJlbGlhbmNlIG9ubHkgZm9yIHRoZSBpbnRl bmRlZCBwdXJwb3NlIGluIGNvbXBsaWFuY2Ugb2YgdGhlIHJlbHlpbmcgcGFydHkg b2JsaWdhdGlvbnMuMDUGA1UdHwQuMCwwKqAooCaGJGh0dHA6Ly9jcmwuc3RhcnRz c2wuY29tL2NydDQtY3JsLmNybDCBjgYIKwYBBQUHAQEEgYEwfzA5BggrBgEFBQcw AYYtaHR0cDovL29jc3Auc3RhcnRzc2wuY29tL3N1Yi9jbGFzczQvc2VydmVyL2Nh MEIGCCsGAQUFBzAChjZodHRwOi8vYWlhLnN0YXJ0c3NsLmNvbS9jZXJ0cy9zdWIu Y2xhc3M0LnNlcnZlci5jYS5jcnQwIwYDVR0SBBwwGoYYaHR0cDovL3d3dy5zdGFy dHNzbC5jb20vMA0GCSqGSIb3DQEBCwUAA4IBAQAhVzgSJ5c+b3dmtU6larmJBTXr m6vrP7lMDHWbHMQwoSWg3jpaw7OesKHwu95zH2VZ7YIcR6Wv0Gm4o52vZaAGlPLe ifC3OzYQPadY4Vsp0sxckd+NhSOdL27uH8I9Ph/CqBByTle+cF0WVdu16EXu43MD SgRfA+MHCh2l3pYjBe9bor8O8YrHdYpG5zhg/EZlOKEFa96jiLhYkg4QUO+W314q C9CfAK1qyUlHsySJiaZGb8rAI8zZpz5CqlbajiG24RFKFM+zR/8d6RMdIvdaGeXk fhgnuo6Pc+PSFFzlO5GgRTYhoqSt5/sN4RlCGHh+JVSJyTDmEddxPMZZXQf/ -----END CERTIFICATE----- subject=/C=DE/ST=Berlin/L=Berlin/postalCode=10965/street=Methfesselstra\xDFe 38/O=Posteo e.K./CN=www.posteo.de/emailAddress=postmaster@posteo.de/serialNumber=HRA 47592/businessCategory=Private Organization/1.3.6.1.4.1.311.60.2.1.1=Charlottenburg/1.3.6.1.4.1.311.60.2.1.2=Berlin/1.3.6.1.4.1.311.60.2.1.3=DE issuer=/C=IL/O=StartCom Ltd./OU=StartCom Certification Authority/CN=StartCom Extended Validation Server CA --- No client certificate CA names sent --- SSL handshake has read 4310 bytes and written 323 bytes --- New, TLSv1/SSLv3, Cipher is ECDHE-RSA-AES256-SHA Server public key is 2048 bit Secure Renegotiation IS supported Compression: NONE Expansion: NONE SSL-Session: Protocol : SSLv3 Cipher : ECDHE-RSA-AES256-SHA Session-ID: E3E35EA4BFEC2C440A5FF78E44DB89D7E64CF7B07256D3AEE6BE8D9DAF0DD9AE Session-ID-ctx: Master-Key: 2CFEC2CA1676DBA055CA315A142D4101611B44785C1DA8A1873A530737F16E0B62F87525FDFE6853683A0D49F982CDF1 Key-Arg : None PSK identity: None PSK identity hint: None SRP username: None Start Time: 1413453065 Timeout : 7200 (sec) Verify return code: 20 (unable to get local issuer certificate) --- 250 DSN