Invoices not received by Customer

Hi,

We are experiencing a glitch since yesterday with our invoices going out from MYOB. Every time an invoice is sent to the customer, a copy comes to our payments folder inbox as well. However since yesterday, the invoices are going to our Microsoft quarantine as suspected phishing emails. These invoices are not being received at customer end as well. We are not sure if its the same case at their end too.

We have had to manually send the PDF to these customers again. When we release it from quarantine, it reflects in our inbox but we have no idea if it is received at customer side. This is a major concern is we have invoices not being received by our customer.

The issue started yesterday and has not been resolved yet. The invoices sent this monrning also showed up in quarnatine at our end. Can someone please look into the matter?