The only thing I can think of is to set the number of days to sync messages, shown below. But I'm not sure if this is what you're after. If it is go to Settings > Mail, Contacts, Calendars select the email account you wish to change.
This will then only sync emails from the last week for example. In the screenshot all email messages would be synced to the iPhone.
Message was edited by: Michael Bratley
I know about this, but it will apply to all of my mailboxes at once. My problem is that I have multiple mailboxes, some for example have emails related to a business trip that might be set up 6 months ahead of time. These would have various details about flights, hotels, usual stuff. I would have this in a separate mailbox call Travel. However, unless I have set up the settings page that you showed for a long time (synch for 6 months say), this mailbox will be empty when I look at it. If I set the page to 6 months then every email I have for that period is on my phone which will swamp it. What I have not been able to figure out is if you can set the mail days to synch for a specific mailbox - not simply for all mailboxes on your exchange server.
Thanks, that is what I was afraid of.
This seems to me to be a simple issue that would be very useful. It would be nice to be able to set up a sub-mailbox on a single account that can store files for a longer period - or for that matter, once it synchs something, it simply keeps it there until you delete it. The rest of your boxes can have the revolving cycle based on how many days you want to save.
I suspect that getting this done would take a few million folks indicating it was desirable. Alas...