What is SPF ?

Email Security :-

Now a day's Email Security is a big concern, without Mail administrator we can't judge any mail that this came from correct domain owner's SMTP Server or not

On June 2003 new standard was published to get rid of this problem "SPF"

What is SPF?

Sender Policy Framework (SPF) is an email validation system designed to prevent email spam by detecting email spoofing, a common vulnerability, by verifying sender IP addresses. SPF allows administrators to specify which hosts are allowed to send mail from a given domain by creating a specific SPF record (or TXT record) in the Domain Name System (DNS). Mail exchangers use the DNS to check that mail from a given domain is being sent by a host sanctioned by that domain's administrators.

Sender Policy Framework is defined in IETF publication RFC 4408.

For more details you can refer to :-

http://en.wikipedia.org/wiki/Sender_Policy_Framework

Note :- if I'm breaking any compliance without my knowledge, please update on my blog so I'll be notified & remove those content.

Understanding Disclaimers in Exchange 2010

http://technet.microsoft.com/en-us/library/bb124352.aspx

What happens when we run new mailbox creation wizard in Exchange 2003


This adds below attributes :-
HomeMDB : home location of mailbox in database
Homemta : native mta
Legacyexchangedn : used for compatibility with exchange 5.5
Mail : primary email address
Mailnickname : maillbox alias
Msexchhomeserver : the server which your mailbox is located
Msexchmailboxguid : guid for primary sam account of mailbox
Msexchmailboxsecuritydescriptor : defines mailbox rights
Proxyaddresses - additional address

Also this set permission to Self only, that’s why mailbox is created only after sending mail to that user Or when user log in.

How to check Last Domain Logon of a User

Open your Domain Controller.

Start > Run > Adsiedit.msc

go to Domain Partition > find that particular user then Right Click

and check the attribute lastlogon, here you will see a Value like this "128271382742968750"

now open command prompt and run below command to change this to date format

w32tm.exe /ntte 128271382742968750

the Result will be like below :-

148462 05:57:54.2968750 - 6/24/2007 11:27:54 AM (local time)

Note : if you have multiple ADC then you need to check this on all ADC for latest Logon time.