Today I received an email from Ebay which I was reading in my Windows Live environement.

I noticed a small green icon before the message, and at the top of the reading pane.

The popup of the green batch says 'This message is from a trusted sender. To help protect you from phishing scams, we double-checked that it's safe'.

Does anybody knows how this system works ? Why does Live displays this icon ? Do we need to add some headers to our mails or let our server be known as a non-spam trusted mail server ?

We are sending mails to hundreds of named customers and would like to be sure that these mails are not listed as spams.

Thanks in advance.


Up till now the hackers have succeeded in breaking each and every protection. So I would say that the Windows Live message is a positive indication, but that one should still use normal caution.

As regarding what you should add to your own emails, see The Sender ID Framework :

Sender ID seeks to verify that every e-mail message originates from the Internet domain from which it claims to have been sent. This is accomplished by checking the address of the server that sent the mail against a registered list of servers that the domain owner has authorized to send e-mail. This verification is automatically performed by the Internet service provider (ISP) or the recipient's mail server before the e-mail message is delivered.

To use SIDF, e-mail senders and domain owners must publish or declare all of the Internet Protocol (IP) addresses used by their outbound e-mail servers, or the IPs authorized to send e-mail on their behalf, in the Domain Name System (DNS). These IPs are included in a Sender Policy Framework (SPF) text file.

In the best case, all this is already taken care of by your ISP.
But it is best to make sure.

In any case, the safety this method gives is based on the DNS system, which we know can be hacked; on the ISP, which we know may be rogue; and on the contents of the email, which can be forged. So Sender ID is surely hackable.

  • Sender ID/SPF has nothing to do with the green batch. – bzeaman Apr 19 '17 at 11:19
  • @bzeaman: Things might have changed since when this answer was given in 2010. Please give more details about why you think so. – harrymc Apr 19 '17 at 15:41
  • The answer below contains the right explanation for the green batch (superuser.com/a/220105/564772). I've worked with tons of email setups, and Windows Live never showed any of these with this green icon. Without SPF the mail will be marked, without Sender ID nothing will change. Sender ID appears to be obsolete and does not affect current mail systems, in my experience. – bzeaman Apr 19 '17 at 17:09
  • 1
    @bzeaman: Thank you for your input. Future visitors: Please take into account that this answer is today possibly obsolete, or that perhaps Sender ID was never universally implemented. – harrymc Apr 19 '17 at 19:18

From an MSDN security blog post:

[Trusted senders] feature visually identifies legitimate mail from about 100 senders, mostly financial institutions like banks, that are commonly spoofed by identity thieves

So I don't think it's possible to somehow identify yourself as a trusted sender. Probably the initiative must come from Microsoft if you're big enough of a company to be targeted by phishers.

| improve this answer | |

The green sheild is a microsoft anti fraud or pro safety product, I don't know what standards you have to meet to get on the green shield list but it should not effect your mail unless microsoft gets complaints from customers. From windows live hotmail-the green shield Hundreds of financial institutions and other companies are commonly impersonated in email phishing scams. Windows Live Hotmail adds the trusted sender icon—a green shield—next to senders that have been identified as authentic, so it's easier to see which messages are safe. http://explore.live.com/windows-live-hotmail-trusted-sender-using

| improve this answer | |
  • it's not that we have problems sending mails to hotmail accounts. We just noticed that during the past few months we are receiving nore non-delivered notifications from servers than before. Wd only send mails to persons who have subscribed to our mailing list, and we adhere to all known rules (e.g. only links inside the mail to the same domain as the sender etc... ). But if we can improve are emails (by inserting certain headers or whatever), we will certainly do so. We only have to know what to do , of course. – Edelcom Dec 9 '10 at 14:04
  • @Edelcom,sorry but I have not been able to find out how one would be judged as honest,i feel you would require contact with and permission from ms which provides the providence-a guarantee that the mail is from who it say it is.This in it's self could possibly open them up for a law suit if wrong [they said it was my bank,etc] but it should be for all received mail.Any tag in the header that tracks all would still require the receiving softwares ok. Will update when i find out how one would qulafy. – mic84 Dec 9 '10 at 17:22

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.