E-mail sending - spam abuse error - Office 365

Guys,

For the 3th time now i'm having intermittent Email problems. Everytime this issue occurs, it is with sending e-mails from SDPOndemand. This time however i contacted Microsoft, and i have gotten assistance almost immediately. Whilst troubleshooting, we learned a few things:

It affects only e-mail sending
the server SDPOndemand uses to send is 216.52.72.54 which is sender1.manageengine.com
The originating IP belongs to ME (X-Originating-IP: [216.52.72.54]
The issue is intermittent - the last 2 to 3 weeks i've e-mailed without incident
The e-mail settings are unchanged
E-mail sending directly from o365 with the used mailadres in SDPOndemand to whatever e-mail adresses we use, works perfectly - it does NOT work from SDPOndemand.

At the moment we are in communication with Microsoft regarding this case: the person in charge is Sagar Gharge, and refer to case # 30126-7091520. In case technical details are needed, you can contact Sagar at office365support@microsoft.com

So please give this priority. Currently e-mail sending DOES NOT work.

With regards,

Sven