I've been fiddling with Exchange ActiveSync lately, and I'm actually pretty impressed with it-- it's a neat feature. If you're not familiar with it, it basically sends periodic notifications of new mail to your Windows Mobile device; when the device receives the AUTD message, it wakes up and pulls new messages from your Exchange server. This gives you more-or-less continuous access to the contents of your mailbox.

However, there's no obvious way to control how often Exchange ActiveSync sends these notifications to your device. By default, it uses an interval of 15 minutes, but that may not be right for your particular installation. There's a way to control the batching behavior, but it's not obvious: you have to create a new REG_DWORD named BatchingTimer under the Software\Microsoft\Exchange\OMA key (if OMA doesn't exist, create it first). Possible values are:

• 0 means don't batch at all: send notifications as each individual message arrives. I wouldn't do this if I were you, since every notification will generate an SMS message to your device, and that normally costs money.
  
• Any value below 900000 (which just happens to be the number of milliseconds in 15 minutes, the default interval) will cause the interval to be kept at 15 minutes
  
• Any value above 900000 will be taken as the actual value. For example, 3600000 will set the batching timer to one hour.
  

However, there's no obvious way to control how often Exchange ActiveSync sends these notifications to your device. By default, it uses an interval of 15 minutes, but that may not be right for your particular installation. There's a way to control the batching behavior, but it's not obvious: you have to create a new REG_DWORD named BatchingTimer under the Software\Microsoft\Exchange\OMA key (if OMA doesn't exist, create it first). Possible values are:

• 0 means don't batch at all: send notifications as each individual message arrives. I wouldn't do this if I were you, since every notification will generate an SMS message to your device, and that normally costs money.
  
• Any value below 900000 (which just happens to be the number of milliseconds in 15 minutes, the default interval) will cause the interval to be kept at 15 minutes
  
• Any value above 900000 will be taken as the actual value. For example, 3600000 will set the batching timer to one hour.