OrgName:    Microsoft Corp 
OrgID:      MSFT
Address:    One Microsoft Way
City:       Redmond
StateProv:  WA
PostalCode: 98052
Country:    US
NetRange:   65.52.0.0 - 65.55.255.255 
CIDR:       65.52.0.0/14 
NetName:    MICROSOFT-1BLK
NetHandle:  NET-65-52-0-0-1
Parent:     NET-65-0-0-0-0
NetType:    Direct Assignment
NameServer: NS1.MSFT.NET
NameServer: NS5.MSFT.NET
NameServer: NS2.MSFT.NET
NameServer: NS3.MSFT.NET
NameServer: NS4.MSFT.NET
Comment:    
RegDate:    2001-02-14
Updated:    2004-12-09
RTechHandle: ZM23-ARIN
RTechName:   Microsoft Corporation 
RTechPhone:  +1-425-882-8080
RTechEmail:  noc@microsoft.com 
OrgAbuseHandle: ABUSE231-ARIN
OrgAbuseName:   Abuse 
OrgAbusePhone:  +1-425-882-8080
OrgAbuseEmail:  abuse@microsoft.com
OrgAbuseHandle: HOTMA-ARIN
OrgAbuseName:   Hotmail Abuse 
OrgAbusePhone:  +1-425-882-8080
OrgAbuseEmail:  abuse@hotmail.com
OrgAbuseHandle: MSNAB-ARIN
OrgAbuseName:   MSN ABUSE 
OrgAbusePhone:  +1-425-882-8080
OrgAbuseEmail:  abuse@msn.com
OrgNOCHandle: ZM23-ARIN
OrgNOCName:   Microsoft Corporation 
OrgNOCPhone:  +1-425-882-8080
OrgNOCEmail:  noc@microsoft.com
OrgTechHandle: MSFTP-ARIN
OrgTechName:   MSFT-POC 
OrgTechPhone:  +1-425-882-8080
OrgTechEmail:  iprrms@microsoft.com
И думаете, на этот abuse можно отправить жалобу на спам с ихнего хотмейла? Агащазблин, разбежались.
Abuse@hotmail.com and abuse@msn.com do NOT process spam reports. These accounts only process abusive e-mails in, but not limited, to the following categories: 
• Child exploitation/pornography threats
• Harassment 
• Impersonation of an institution or trademark (like a bank or government agency or charity) also known as Phishing 
• Issues relating to account credentials being compromised (hacked)
А если про спам - это вам на  report_spam@hotmail.com or report_spam@msn.com depending on the spammer’s domain.
Только врожденным ненатурализмом можно объяснить отсутствие этих адресов в ARIN.