Save space zipping Outlook attachments automatically, with Pack Attachments
Pack Attachments is a free Outlook add-in that zips email attachments to help you save space.
The add-in is extremely easy to configure. Just select the folders that you want to be scanned for attachments, your Inbox or anything, and enjoy!
The add-in searches all folders you selected to compress the attached files. Note that you cannot customize the names of zip archives, they are all called “attachments.zip”. If a message contains several attachments, they are all zipped in the same archive.
A commercial version of the add-in provides more flexibility, such as creating a separate archive for each attachment, customizing the name of the archives, etc. If you don’t need these, the free version will work just fine to let you save some space.