I recently downloaded and installed the Owl plug-in for Thunderbird. I am not able to download any attachments. Thunderbird simply states, "Downloading....<name of attachment>" but is never able to download it. I used the trial version of Owl but did not have this problem. I am able to download the attachments when I used my iPhone and when I use "outlook.office.com". I would much rather prefer to use Thunderbird.