Security policies for the iPhone/iPod touch/iPad synchronizing with a NotifyLink Enterprise Server (NLES) require an eight (8) character password when Inactivity Timeout is enabled.
Should the Microsoft Exchange account, which synchronizes with the NotifyLink ActiveSync component, be removed from the device, you can use the following method to restore the original four (4) digit passcode policy on the device.
Once the NLES account is removed from the iPhone, you can get back to the original 4 digit passcode by doing the following:
1) Go to Settings > General > Passcode Lock and enter the old 8 character passcode
2) Tap Turn off the Passcode. Enter the old passcode again.
3) Tap Turn on the Passcode. Enter a new 4 digit passcode if desired.