Can't send email from postfix to hotmail

CappyT is right. The problems comes from the hotmail servers. That's unbelievable, see also the very poor anwers from microsoft to this: microsoft answers

I experienced this problem also with my servers (that are not blacklisted in no way), my messages are perflectly authenticated (spf, dkim) and well formatted. I send emails to thousands of people. Checkink the log, i see:

postfix/smtp[15617]: B05C066C0E: to=EMAIL, relay=mx1.hotmail.com[65.54.188.110]:25, delay=2.8, delays=0.07/0.01/1.2/1.5, dsn=2.0.0, status=sent (250 EMAIL Queued mail for delivery)

This is the same as an Ok acknowledgment for me. I don't receive a bounce responce and the message is never delivered. Conclusion: I have to say to our members to go away from hotmail

Hotmail randomly blocks some IP addresses in order to get you to sign up for there Junk Mail Reporting Partner Program. If you don't you can get error with your mail returned with a message like this:

host mx2.hotmail.com[65.54.188.72] said: 550 SC-001
(BAY004-MC1F54) Unfortunately, messages from xxx.xxx.xxx.xxx weren't sent.
Please contact your Internet service provider since part of their network
is on our block list. You can also refer your provider to
http://mail.live.com…il/troubleshooting.aspx#errors. (in reply to MAIL
FROM command)

To fix this you can fill this form (I believe this one will allow the IP's to send to your address on hotmail):

https://support.msn.com/eform.aspx?productKey=edfsmsbl2&ct=eformts

or this one (this one should allow the server(s) to send to all hotmail addresses):

https://support.msn.com/eform.aspx?productKey=edfsjmrpp&ct=eformts

and if you have a range of IP's with clients VM (where the mails are not your domain), you will need to sign up to Smart Network Data Service here:

https://postmaster.live.com/snds/index.aspx

and enter your servers IP range. Microsoft is making it complicated to get people to sign up, or pay for anti-spam services when people are afraid they might be blacklisted.

You can also verify your blacklisting status here:

http://www.anti-abuse.org/

or here:

http://mxtoolbox.com/

250 <[email protected]> Queued mail for delivery

Server reponded with normal status (250) and informed, that your message was received by the server and queued. Maybe it's in spam, or maybe is blocked, but still with status 250.

To avoid such problems, setup SPF and DKIM.