While looking for a response to your query, I found and even tested this free software called "Mail Attachment Downloader". The download link has been provided below.
Download and install the software from the link provided. Perform 'Authorization Process' which will allow this third party software to download all the attachments from your e-mail.
Please use it and share your experience with us.
A word of caution though, since this is a third party software, privacy of ID and password cannot be ascertained. So my advice is to avoid using this software for downloading attachments of your office e-mail.