Attachments sent using Outlook application are getting corrupted.

Premkumar Solanki 

Afternoon

One of the possible reasons why you are experiencing this error is due to normal.dotm file corruption. To address your concern, we suggest that you delete the normal.dotm file. Microsoft Word will automatically recreate a new normal.dotm file once it is relaunched. It is located in the hidden folder C:\Users\User Name\AppData\Roaming\Microsoft\Templates. 

To be able to view this folder, you have to tick the Show Hidden files, folders and drives radio button in Control Panel. To do so, follow these steps:

1. Press Windows button + X, then click Control Panel.
2. Using the Search option on the upper right corner of Control Panel window, type File Explorer Options.
3. Click File Explorer Options.
4. Click View tab, then tick the Show Hidden files, folders and drives radio button.
5. Click Apply button, then click OK button.
6. Open File Explorer.
7. Type C:\Users\User Name\AppData\Roaming\Microsoft\Templates in the Address Bar then hit Enter.
8. Delete normal.dotm.

If further assistance is needed, don't hesitate to reply on this thread.