The Mail Days to Sync option in the Mail app can be adjusted to show emails from the last day up to as far back as there are emails in your account. If I'm taking the train, I have email waiting for me when I start my commute - rather than downloading it as I rush into London. , 2 weeks: Specify how many past weeks’ worth of email to be automatically delivered to your device. I noticed that the exchange account subfolders rarely sync. it is working on fine with other servers. I made all the changes via the registry, is there a period registry. Touch Email.