On Android, BlueMail opens PDF attachments in its own viewer. To open them in another PDF app instead, such as Adobe Acrobat or WPS Office:
- Go to Settings | Global Settings.
- Tap Advanced Features.
- Tap Open PDF Files, just below Open Web Pages.
- Tap External App.
PDF attachments now open in your phone's default PDF app. If you haven't set one, Android asks which app to use: check it's the one you want before you tap Always. To switch apps later, see How to Change the Default PDF Viewer on Android.
To go back to BlueMail's viewer, choose Default. Don't see Open PDF Files? Update BlueMail.
