Are Hotmail cutting their own throat


UPDATE: Email clients play a role too

While reading back through this article I noticed that it was totally server centric, with no consideration of what an individual email client might be doing to effect an emails deliverability to Hotmail. Email clients are responsible for adding header information which is widely used for aiding in anti spam purposes.

I started playing around with clients rather than concentrating on server setup, and I've had some interesting results. I can send to Hotmail without a problem using Outlook 2003, but no cigar with Mozilla Thunderbird. I haven't tested other email clients yet, but I think that this suggests that the headers the email clients add to an email also play a crucial role in determining if the mail gets through or not. This is BAD news because as a system admin there is generally very little you can do about this. I'll be interested to continue testing, especially with the user-agent and x-mailer headers.


This one should not be a hard one to come to. If people are not able to be confident that mail sent to Hotmail will get there, then why use their services? Especially when there are so many other players in the field. I have now configured rules for this website that ban the use of Hotmail addresses during signup, and have configured my email server to send a message to any of my users sending to a Hotmail account informing them that their email is unlikely to get through. I realise that me banning Hotmail is not going to make any difference, but get 1000, then 10,000 the 100,000 other webmasters just like me doing the same thing and you really have to ask yourself. Are Hotmail cutting their own throat?


Anonymous's picture

I found a solution: :) hope it works for you

I tried to find solution on IIS part, and read the article on this page. Honestly it helped a lot.

The problem is not IIS SMTP settings. After I read here, I tried my IIS with my outlook, and hotmail received my messages. But hotmail doesn't receive messages from WEB application which is ASP.NET. God sake it is a Microsoft product.


After I added headers to my message from my ASP.Net application, hotmail started to receive my emails. I don't know how long it will continue. I just post here immediatelly, so you guys don't have to struggle like me any more.

Here is How I added headers to my outgoing email:

Dim objMail As New System.Web.Mail.MailMessage

objMail.From = ""
objMail.To = ""

objMail.Subject = "Subject line comes here"
objMail.Body = "Message body goes here"

objMail.BodyFormat = Mail.MailFormat.Text

objMail.Headers.Add("X-Mailer", "ASP.NET")
SmtpMail.SmtpServer = "My Local SMTP Server Address"


Hope it helps;

Emin Pala

Anonymous's picture

Hotmail also suddenly deletes Mac Outlook Express 5 mail !

Not only is the client the main error in hotmail's pathetic SILENT deletion of incoming mail, such as the thunderbird version you tested, but my own tests show that emial sent from an equally non-spamming small server 100% configured correctly also is lost, so long as the CLIENT email program used to create the mail is Microsofts own Mac version of the older Outlook Express 5.0

So the client creates the spam score. The same exact email sent other ways goes through.


I will direct everyone to this page to now say goodbye to hotmail.

Hotmail (which microsoft paid nearly a billion dollars for I think) is as of this month, a dead service.

Long live Yahoo (gmail is better but archives your emails).

CRAZY microsoft! What were they thinking?

I might consider trying to add a different X-Mailer header as suggested on the email server to overcome microsofts retardation.

Anonymous's picture

Me too (yes, another one)

I have what appears to be the exact same problem. Thanks for the write up!


Anonymous's picture

our hotmail experience

I've been embroiled in this hotmail cr*p for the past month.
Countless hours lost. And still no resolution.
Here are some things we've discovered:

-If a hotmail users sends an email, and the recepient replies, the email will make it through.
-There was some success with the following header:
To: "Test User{or the actual display name of the user}"
versus the usual:
-Someone in the company discovered that sending as html (Content-Type: multipart/alternative) was successful 70% of the time. Sending as text/plain went to spam folder everytime.

Anonymous's picture

My Hotmail Account

Interesting comments ab't service has been nil for weeks...while looking into the problelm, I stumbled on your site...I am an illiterate ludite..what can i do? I am taking my hard drive to an"expert" and seeing if there is any hope for me and my "toweer of power"!!!! Moreabout this later... if me and my computer survive...or it will be an Apple for me!! dont know how to sign off, except :
Hoping to communicate with you soon. BP Canada

Anonymous's picture

HotPOP Account

E-mail sent from a HotPOP account to Hotmail are also lost into oblivion.

Hotmail also stoped working with Entourage 2001and OE5 Mac. I can get e-mails but not send.

Anonymous's picture

I am having exactly the same

I am having exactly the same problem. Outlooks arrives, mutt arrives, CLI arrives, thunderbird, evolution, squirrel mail don't.

But, if I send the same email to a gmail account and hotmail account at the same time (by filling out 2 to: fields) it gets through!

Also, as you said, replying to a hotmail message also gets through.

Anonymous's picture

Same problem here...

Two months ago, i've started a few sites. Sometimes i would send out a few emails not only to test the server, but also to test some site features (formmails, newsletters,...). Those emails were sent to Hotmail and other email services (only to accounts owned by me).

Even though some mail was being marked as spam, all messages were arriving without any issues. But since September 1st, email sent to Hotmail accounts, doesn't arrive or bounces back. It simply vanishes !

All email sent to other services arrives, even though sometimes is filtered as spam.

I've asked for support from my host and they were very helpful. I really don't see any problem from their end. My SPF records are ok and my DNS report is similar to the one from the IIS Aid (everything is ok with just a few warnings).

At this time, if i send any mail from Outlook or Webmail (Squirrelmail), it simply vanishes. But if the email sent is generated by the server (from a formmail or a maillist) it's delivered... weird...

I can also confirm what other posters said, that if you send a message from Hotmail to the mail at your domain and the reply... the message is received at Hotmail without any problems.

Anonymous's picture


If you currently have commas, try removing all commas from your SPF record, especially if you have more than one domain. Then wait 3-6 hrs and then notify Hotmail of the change -

Sounds strange, but it worked for me.

Anonymous's picture

same problem here

We've got the same problem. Mail sent from TBird to msn is dropped without any bounced message eventhough the outgoing mail server identifies the messages as queued for delivery. However if the exact same message is sent with Outlook, the outgoing mail server has the exact same "message queued for delivery" message but the mail goes through no problem.