Describe the issue

When sending a ZUGFeRD e-document from Business Central for Germany via the Document Sending Profile and workflow, the email attachment is generated with a .xml file extension even though the file content is a valid PDF (ZUGFeRD-in-PDF).

Renaming the attachment from .xml to .pdf makes the document valid.

One part of this change should be done in "E-Document Core App" and the other part in the app "E-Document for Germany". Generally speaking, sending E-Documents as attachment in an E-Mail should be able to recognize if the file is an xml or pdf.

Expected behavior

• The email attachment should be a PDF file with the .pdf extension containing the embedded ZUGFeRD XML payload.
• The generated attachment name and MIME type should align with PDF (e.g., application/pdf).
• No manual renaming should be required by the sender or recipient.

Steps to reproduce

1. Use Business Central for Germany.
2. Enable E-Document Service for ZUGFeRD.
3. In setup:
   • Buyer Reference Mandatory = Yes
   • Buyer Reference = Your Reference
4. Configure a Workflow for ZUGFeRD (per docs).
5. Configure a Document Sending Profile for ZUGFeRD (per docs):
   • Email = Yes
   • E-Mail Attachment = E-Document
   • Electronic Document = E-Document Workflow
   • E-Document Workflow = MS-EDOCTOS-01
6. Mark this sending profile as the default profile.
7. Assign the sending profile to a Customer.
8. Create a new Sales Invoice for the same Customer.
9. Post the Sales Invoice.
10. Open the Posted Sales Invoice and choose Send.
11. Confirm the dialog.
12. Observed: The Email Editor appears with an attachment that has a .xml extension. - If downloaded and renamed to .pdf, the ZUGFeRD file is valid.

Additional context

No response

I will provide a fix for a bug

• I will provide a fix for a bug