Cannot send email alerts using SMTP server with Office 365
Problem
I tried to send email alerts using the PMC user interface, but received this error message: "MessagingException --> Exception reading response"
Cause
The recipients' mailboxes are hosted within Microsoft 365 or Office 365, and the SMTP server of Microsoft Office 365 or Office 365 is not configured to send mail directly from applications to the mailboxes.
Solution
Set up Direct Send through Office365. See Option 2 in this Microsoft article: https://support.office.com/en-us/article/How-to-set-up-a-multifunction-device-or-application-to-send-email-using-Office-365-69f58e99-c550-4274-ad18-c805d654b4c4