You’ve set up your own mail server and all runs like a charm. Well, you may find out that your messages are not delivered to any Hotmail account. Yes I know, your log shows that the massage has been accepted by the Hotmail server, but has it been delivered? Even to the junk folder? Try it out and if it hasn’t, read on!

So let’s name and then face the enemy!

The enemy is called “Microsoft SmartScreen”. We will find out later that the word smart is not appropriate.

First of all let’s make sure that your server is sending the message successfully. Create a Hotmail test account if not already done. Send a test email from your server to the Hotmail address and check the syslog.

cat /var/log/syslog | grep hotmail.com

Feb 18 15:56:16 yourserver postfix/submission/smtp[22861]: ED63E62643: to=<your_test_account@hotmail.com>, relay=mx2.hotmail.com[207.46.8.167]:25, delay=1.4, delays=0.07/0.02/0.46/0.85, dsn=2.0.0, status=sent (250 <20150218205614.W7RLwBFP35lDuQdZEA3@yourdomain.com> Queued mail for delivery)

We can see that we successfully sent the message. Check the Hotmail Inbox and Junk folder. No email there? Welcome in the club! So let’s fix that!

What you need to do (you can skip the first 5 steps if you followed my “Mailserver How To” for setting up your server):

Setup a SPF record

Setup DKIM

Setup a DMARC record

Setup a reverse DNS record

HELO must be a host name not an IP

Make sure that your IP is not on a blacklist

Use a static IP address for your server

Sign up for JMRP and SNDS

Try this if your IP is blacklisted at Hotmail.

The Hotmail guidelines are listed here.

After all the above steps have been completed (wait 24 hours after DNS changed to make sure that Hotmail has your latest DNS entries), then it’s time to do some testing.

Let’s use telnet to be sure that SmartScreen is not filtering our message because of the email formatting, or for some other strange reason.

your@server:~$ telnet mx1.hotmail.com 25

Trying 207.46.8.167... Connected to mx1.hotmail.com. Escape character is '^]'. 220 BAY004-MC5F36.hotmail.com Sending unsolicited commercial or bulk e-mail to Microsoft's computer network is prohibited. Other restrictions are found at http://privacy.microsoft.com/en-us/anti-spam.mspx. Fri, 20 Feb 2015 06:58:10 -0800 helo yourdomain.com 250 BAY004-MC5F36.hotmail.com (3.21.0.160) Hello [95.85.37.111] MAIL FROM:yourname@yourdomain.com 250 yourname@yourdomain.com....Sender OK RCPT TO:your_test_account@hotmail.com 250 your_test_account@hotmail.com DATA 354 Start mail input; end with <CRLF>.<CRLF> SUBJECT:Hi Please SmartScreen god deliver my messages! . 250 <BAY004-MC5F369RKLpg000ab564@BAY004-MC5F36.hotmail.com> Queued mail for delivery

You should have successfully received the message in your Hotmail mailbox, most likely in the JUNK folder.

Now try to send from your email client and it should give you the same result.

Why are your emails ending up in the junk folder?

Well, I think SmartScreen is too smart for us!

It’s a question of IP reputation. If you are running a small private email server, there is not a lot you can do unfortunately. You will have to tell your friends to look in the Junk folder when sending them the first email.

For the commercial mail server:

Microsoft is considering receiving a small email volume from a mail server as suspicious. You need to send high volumes to get reputation. And you want to sign up for a Returnpath certificate (not free).

After all that said, it seems not very smart to me if a message is considered SPAM, following all the above measures.

Most likely Gmail is also sending your messages to the SPAM folder.

Submit a simple request to fix this.