We currently have a mixed environment with office 365 and an onpremises Exchange server 2007. Our MX is still pointing to out onpremises Exchange 2007, meaning that communication are coming through our exchange first and then being forwarded to our Exchange Online account.
All of a sudden since this Monday, a good amount of spam emails are being forwarded to our inboxes(not even to our junk mail). It seems that our spam email settings are not working properly.
I have check on the spam settings and they look ok. I have talked to Office 365 and we ended on setting up a policy to delete messages from those spam domains but apparently spammers keep on changing their addresses so the policy is not that effective.
Any idea what else I can check?