Using Classic Outlook on Windows for personal email, calendar, and contact management
Hi,
Are you having issues with specific attachments like a PDF or a specific one?
Troubleshoot attachment problems in Outlook for Windows
https://support.microsoft.com/en-us/outlook/troubleshoot-attachment-problems-in-outlook-for-windows
Press Windows+R keys on the keyboard, or Right-click Start on the Taskbar and choose Run.
Type "Outlook.exe /safe"
Press Enter.
Kindly let me know if in Safe Mode attachments work.
I look forward to hearing from you to get the results of the troubleshooting.