Mail Sender adapter issue in PO7.4

Hello Experts,

We are migrating from PI7.0 to PO7.4, where in we are struck up with an issue of Mail Sender Interface.

Here we have a scenario of Mail to Proxy where we are processing attachment(CSV file). But here when I we run the interface mail body is being processed not the attachment. Also could nt see the Payload as when I click on the Attachment payload a pop up is coming and closing automatically.

Can someone please suggest where it went wrong as this is working in existing PI7.0 version.

Thanks.

VR