How to Delete Email Download Attachments in Mac OS Xby Sophie Southern
Apple Mail, the default email application in Mac OS X, lets you view email attachments directly in the message window. Mac OS X keeps a backup of all your downloaded email attachments in case you need to access something after you've deleted the message, but this backup can end up taking up a lot of space on your hard drive over time. You can clear out the folder created by Mail on your Mac and delete the previously downloaded email attachments you no longer need.
Click the "Finder" icon in your Dock to open a new Finder window. Select "View" from the top menu bar and then select "As Columns." You can also use the icons in your Finder window and the keyboard shortcut "Command+3" to set your view to columns in the Finder.
Click the shortcut link for your user account in the left column of the Finder window. Click "Library" and then click "Mail." It is important that you use this exact path.
Click the folder for the account for which you want to delete attachments. It should begin with the type of account, such as "Mac" or "IMAP," followed by the email address.
Click the folder titled "Deleted Messages," followed by the name of your mailbox. Click the "Attachments" folder. Click any item in the folder and hold the "Command+A" keys to select all. Move the items to your Trash. If you don't see an "Attachments" folder, your Mac is not storing attachments from your deleted messages.
Click the file titled "INBOX.imapmbox" if you want to delete all attachments in the email inbox on your Mac. Depending on the type of email account you use the file may also be "INBOX.mbox."
Click the "Attachments" folder. Again, click any item in the window and hold the "Command+A" keys to select all. Move the items to your Trash. Empty your Trash to permanently delete the attachments from your Mac.