HTTP Header reponses of mail-attachment.googleusercontent.com is the information we get when HTTP request sent to a server from connecting clients(e.g. chrome, firefox). When you input an address into your browser it sends a request to the server hosting the domain and the server responds. HTTP Header information is not directly displayed by normal web browsers like chrome, firefox etc.
HTTP/1.1 404 Not Found Content-Type: text/html; charset=UTF-8 X-Content-Type-Options: nosniff Date: Thu, 14 Feb 2013 23:25:51 GMT Server: sffe Content-Length: 931 X-XSS-Protection: 1; mode=block
DNS Record Analysis
There are total 5 records in domain name system (DNS) of mail-attachment.googleusercontent.com, which includes 3 Address(A) records, 1 IPv6 Address(AAAA) record and 1 Canonical Name(CNAME) record.
Host Name of the node to which this record pertains
Type Type of resource record in symbolic representation.
IP/Target
TTL Count of seconds that the resource record stays valid.
Extra Info Additional resource record-specific data
googlehosted.l.googleusercontent.com
A Address Record: A 32-bit IPv4 address, most commonly used to map hostnames to an IP address of the host, but also used for DNSBLs, storing subnet masks in RFC 1101.
74.125.228.10
300
googlehosted.l.googleusercontent.com
A Address Record: A 32-bit IPv4 address, most commonly used to map hostnames to an IP address of the host, but also used for DNSBLs, storing subnet masks in RFC 1101.
74.125.228.12
300
googlehosted.l.googleusercontent.com
A Address Record: A 32-bit IPv4 address, most commonly used to map hostnames to an IP address of the host, but also used for DNSBLs, storing subnet masks in RFC 1101.
74.125.228.11
300
googlehosted.l.googleusercontent.com
AAAA IPv6 Address Record: A 128-bit IPv6 address, most commonly used to map hostnames to an IP address of the host.
300
ipv6: 2607:f8b0:4004:800::100b
mail-attachment.googleusercontent.com
CNAME Canonical Name Record: Alias of one name to another: the DNS lookup will continue by retrying the lookup with the new name.