Apple’s Mail.app email client gets a lot of flack for being a bandwidth hog when used to access Gmail via IMAP. The reason for the bandwidth sink has to do with the way that Gmail archives email. To cut a long story short: no matter how you label or delete your email in Gmail it is always stored in a master folder that contains all the email you have ever sent and received, even deleted messages. Keeping the ‘All Mail’ folder in constant sync via IMAP consumes a lot of bandwidth. But there is a way to set up your Gmail -> Mail.app integration that makes this problem disappear, optimises bandwidth usage and improves the experience of using Gmail with Mail.app, which is an awesome mail application, once you have it configured correctly.
And it goes a little something like this:
1. The first thing to do is enable the ‘Advanced IMAP Controls’ plugin for Gmail in Google Labs. Log in to Gmail on the Web, click on ‘Settings’ and then on ‘Labs’. Scroll down to ‘Advanced IMAP Controls’ and check the radio button for ‘Enable’. Then scroll down to the bottom of the page and click on ‘Save Changes’. While we’re at it, let’s acknowledge Jamie N who created this plugin. Respect.
2*.* Next we need to prepare Gmail for IMAP access. You’ve probably done this already, but activating Advanced IMAP Controls enables extra options. Click on ‘Settings’ in Gmail and then on ‘Forwarding and POP/IMAP’. Check ‘Enable IMAP’, ‘Immediately expunge messages when I mark them deleted in IMAP’ and then ‘Save Changes’.
3. Next click on ‘Labels’ where the Advanced IMAP Controls plugin has added the ability to select which labels, that are really just IMAP folders, are exposed to IMAP. Ensure that the ‘All Mail’ label is *not * set to show in IMAP, and that your Inbox, Sent Mail and Drafts folders are selected for ‘Show in IMAP’. You can also enable Starred Mail or other labels, including those you have created. For my setup I stick to just the three necessities for Mail.app integration.
Your Gmail is now configured for rock-solid Mail.app integration and you can go ahead and configure Mail.app using Google’s recommended settings, but with one exception: Google’s recommendations say you shouldn’t explicitly use Gmail’s sent mail folder, but I prefer to do so just to minimise folder-clutter in Mail.app.
With these optimisations in place Mail.app will no longer be a bandwidth hog and your Gmail access using the Apple client should be somewhat snappier and a whole lot cleaner.