PDF File is Corrupted or Damaged when the Attachment is Opened

Hello,

I have three Similar forms which are triggered from Sales Order, Delivery & Shipment respectively. Now, the requirement is to send the Form Output as PDF Attachment in a mail. But the Problem I am facing is that the Shipment Output goes as PDF attachment and when opened, it is displayed correctly. However, when the Sales Order & Delivery PDFs are sent as attachments, then the Adobe Reader says

"The File is Corrupted or damaged hence cannot be opened". This is the Message I get when processed from the Delivery. For the Sales Order, the Mail Output triggers with an error in SOST.

We have the Mail Ports open during Testing and I am using the latest version of Adobe Reader. Can someone give me any resolution to handle the Damaged PDF File?

Thanks and Regards,

Venkat Phani Prasad Konduri