Android OS will only allow you to save a file with the same name a limited number of times. You must remove a copy of the saved file or rename one of the existing files in order to save it in Outlook Mobile. Follow these steps to resolve the issue:
- From the Files app on your Android device select the section called Downloads.
- Once in the Downloads folder, search for the name of the file you want to save.
- Rename or remove one or more copies of the file.
- Return to Outlook Mobile and save the file.