Problems with mail delivery to hotmail.com
Earlier today June 3, 2020 there was a report of failed messages being delivered to hotmail.com or outlook.com.
We’ve rectified the problem by relaying mail to other servers and have opened a case with Microsoft to check on why our server was banned.
Report came in at 8:30am PST, and was fixed approximately 10am PST.
Only users connected with our Hosted Exchange were affected.