SMTP error from remote mail server after MAIL FROM:SIZE=3216: host mx1.hotmail.com [65.54.188.72]: 550 SC-001 (BAY0-MC1-F41) Unfortunately, messages from 72.55.188.12 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/mail/troubleshooting.aspx#errors.
It's hard to understand what to do next since there is no visible service for Hotmail. After some digging I found this online form on Microsoft Support site:
https://support.msn.com/eform.aspx?productKey=edfsesc&ct=eformts
Filled it up. Do not know if the issue will be solved, but at least they ask all the right questions there :)
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