On-Prem Exchange Emails Blocked/Delayed by Microsoft365 Domains

Copper Contributor

I am hoping that someone can help me send emails from an On-Prem Exchange 2016 Server to Microsoft 365 Tenants. Let me explain.

Angelbeat runs Virtual Seminars for Microsoft. More info at www.angelbeat.com. I setup angelbeatseminars.com to send out newsletters to our 300,000 database of optin email addresses, using a Dell Server running Exchange 2016.

 

We are having significant problems sending emails from angelbeatseminars.com to Microsoft365 domains; all the emails get delayed/blocked. I have setup angelbeatseminars.com with spf, dkim, reverse DNS lookup, etc. but still it is not working.

 

Can someone help??? PLEASE. Email me at rgerber@angelbeat.com.

 

1 Reply
Check the header information of one of the delayed email and put the complete header in mxtoolbox analyze header.
https://mxtoolbox.com/EmailHeaders.aspx
See the hops and you should get some answers where the delay is happening.