Direct Push Technology (Activesync)

Is there any way to get this to only request a sync if new mail arrives? Normally it requests an activesync if there are 'any' changes made to the exchange mailbox.

Basically I interact quite a bit with outlook at work throughout the day, but I'm in/out of the office quite a bit. It seems that it is always doing an activesync which ties up the line and all my calls go directly to voicemail.

My current carrier is US Cellular, on a 1X network if it matters.

Is this normally how it works? Tieing up the phone line during activesync?

Any help would be appreciated!