How do I remove pending/in-progress downloads
Have you tried a file explorer like ES File Explorer or My Files, which comes with later versions of Android? If go to the Download folder is the half file present? A completely downloaded file will present a long list of options if you long press the file, allowing you to cut/copy/rename/delete. Possibly it will also appear on a halfway complete download to allow you to delete. Then revisit the gmail message to restart the download if you want.Remember that the target folder might have been specified other than the Download folder.Good Luck.