How can I stop Mail.app from automatically downloading full messages? I'm a college student and a student employee at my college's IT office. We recently upgraded to Google Apps for Education for our college email, and we also have a high proportion of Mac users on campus (students, faculty, staff, and administrators). 

My manager in IT pointed out that since Mavericks came out, it seems as though Mail.app is automatically downloading the entirety of all messages from the server for caching purposes so Spotlight can search them instantly. For normal users, I'd imagine this is fine. We have some institutional users with 20+ years of email (hundreds of thousands of messages), and this new feature of Mac Mail is slowing their computers down significantly. My manager said that Mail.app previously just downloaded message headers, but now it's downloading full text and attachments. From searching this topic on AskDifferent, I know that it's possible to turn off auto-downloading of attachments by going to Preferences>Accounts>Advanced> and unchecking "Automatically download attachments."

Is there a way to turn off the auto-downloading of full message text as well, and force Mail.app to only download headers of archived mail?
You may try a workaround: users with high email count can configure their Google Apps accounts not to sync more than 1000 emails per label (or folder).   

Each user will have to:  


Go to their Gmail interface  
Go to Settings (by clicking on the gear in the upper-right hand side of the page)  
Select the Forwarding and POP/IMAP tab  
Look for "Folder Size Limit "and check "Limit IMAP folders to contain no more than this many messages" and select 1000 (or another number that seems appropriate)