Certificate summary -

Owner: *.us1.list-manage.com, "The Rocket Science Group, LLC", L=Atlanta, ST=Georgia, US

Issuer: Thawte SSL CA, "Thawte, Inc.", US

Expiration: Wed Apr 29 19:59:59 EDT 2015

MD5: D2:E1:DF:C6:C4:E6:55:40:46:A5:1C:04:B4:8A:90:B5

Hash: Owner Hash=9c387249, Issuer Hash=346c446a

Information extracted out of the certificate:

Owner: CN=*.us1.list-manage.com, O="The Rocket Science Group, LLC",
L=Atlanta, ST=Georgia, C=US
Issuer: CN=Thawte SSL CA, O="Thawte, Inc.", C=US
Serial number: 3ef78fb7068b506690c6225f5463971
Valid from: Sun Apr 28 20:00:00 EDT 2013 until: Wed Apr 29 19:59:59 EDT
2015
Certificate fingerprints:
	 MD5:  D2:E1:DF:C6:C4:E6:55:40:46:A5:1C:04:B4:8A:90:B5
	 SHA1: 65:64:EB:0F:3A:E2:08:9C:5D:F3:24:F9:C4:70:A9:ED:9A:9C:4F:25
	 SHA256:
72:BD:EC:53:3A:85:AF:D1:71:FA:71:1B:99:01:04:53:8D:8F:DA:4E:39:C2:70:F4:06:
55:51:1A:E4:78:0A:87
	 Signature algorithm name: SHA1withRSA
	 Version: 3

Extensions: 

#1: ObjectId: 1.3.6.1.5.5.7.1.1 Criticality=false
AuthorityInfoAccess [
  [
   accessMethod: ocsp
   accessLocation: URIName: http://ocsp.thawte.com
, 
   accessMethod: caIssuers
   accessLocation: URIName: http://svr-ov-aia.thawte.com/ThawteOV.cer
]
]

#2: ObjectId: 2.5.29.35 Criticality=false
AuthorityKeyIdentifier [
KeyIdentifier [
0000: A7 A2 83 BB 34 45 40 3D	FC D5 30 4F 12 B9 3E A1  ....4E@=..0O..>.
0010: 01 9F F6 DB					 ....
]
]

#3: ObjectId: 2.5.29.19 Criticality=false
BasicConstraints:[
  CA:false
  PathLen: undefined
]

#4: ObjectId: 2.5.29.31 Criticality=false
CRLDistributionPoints [
  [DistributionPoint:
     [URIName: http://svr-ov-crl.thawte.com/ThawteOV.crl]
]]

#5: ObjectId: 2.5.29.32 Criticality=false
CertificatePolicies [
  [CertificatePolicyId: [2.16.840.1.113733.1.7.54]
[PolicyQualifierInfo: [
  qualifierID: 1.3.6.1.5.5.7.2.1
  qualifier: 0000: 16 1A 68 74 74 70 73 3A   2F 2F 77 77 77 2E 74 68 
..https://www.th
0010: 61 77 74 65 2E 63 6F 6D	2F 63 70 73		 awte.com/cps

]]  ]
]

#6: ObjectId: 2.5.29.37 Criticality=false
ExtendedKeyUsages [
  serverAuth
  clientAuth
]

#7: ObjectId: 2.5.29.15 Criticality=true
KeyUsage [
  DigitalSignature
  Key_Encipherment
]

#8: ObjectId: 2.5.29.17 Criticality=false
SubjectAlternativeName [
  DNSName: *.us1.list-manage.com
]

Certificate in PEM format (Base64 encoded X.509):

-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Visit the Web site using this certificate: https://www.list-manage.com

Search for the certificate of the issuer.