Until today I have occasionally had a problem or other with sending emails that were easily overcome.
However since yesterday I noticed that microsoft is blocking all my emails to outlook.com. live.com and hotmail.com for no reason because I rarely send emails to these domains.
The returned message is this:
This message was created automatically by mail delivery software.
A message that you sent could not be delivered to one or more of its recipients. This is a permanent error. The following address(es) failed:
host outlook-com.olc.protection.outlook.com [184.108.40.206]
SMTP error from remote mail server after pipelined MAIL FROM:<firstname.lastname@example.org> SIZE=17985:
550 5.7.1 Unfortunately, messages from [220.127.116.11] weren't sent. Please contact your Internet service provider since part of their network is on our block list (S3140). You can also refer your provider to http://mail.live.com/mail/troubleshooting.aspx#errors. [SN1NAM01FT036.eop-nam01.prod.protection.outlook.com]