Hi, I recommend that you access your email via web browser (if possible), search for the problematic PDF and delete the email that contains this attachment. This will prevent Outlook from downloading the same email over again.
If you cannot access your email account in your web browser, you can follow the steps below:
- Disable Avast File Shield temporarily: https://support.avast.com/en-ww/article/use-mac-security/#idt_031
- Quit and reopen Outlook.
- Search for the detected PDF and delete the email that contains this attachment.
- Enable Avast File Shield again.