I would recommend contacting the support team that works with your account for specific follow up. This is quite unusual behavior and something that would need additional research. I know from my experience, any time we have seen an issue like this upon further investigation we discovered that the sending server was sending us multiple copies of the same message, but support will need to review your specific details to determine what is going on.
Thank you so much for your response.
I opened the ticket and asked to provid me with logs at the time the problem occured.
I was questioning if the sender's server kept sending the same e-mail or not.
McAfee log shows each duplicate has a different message ID. I thought if the sender is sending the same mail, all e-mail should have the same message ID.