I've noticed that with other ROMs, including Stock ROMs. I'm not sure how the OS is handling send/receive requests, and it may require re-writing part of the low-level OS itself.
Speaking of Send/Receive, I've been using an automated progy to save my battery. Basically, I set all of my email accounts to manual check, and then copy this program (below) somewhere in windows/start menu. Then I just create an icon/pointer to it.
My concern was that multiple email accounts periodically checking for new mail may potentially be checking at multiple times. This would keep your data connection "live" unnecessarily.
Say each account is set up to check every 15 mins for new email. If you have 15 email accounts (just for example), and you "save" the "check every 15 mins" option at different times, each account may run on its own independent 15 min schedule. Ex: If each account is configured one minute apart, you could have each account checking every minute of every 15 min interval. I hope I explained this well enough to make sense.
But having all accounts on the "same" 15 min schedule would avoid this. That's what this configuration ensures. The only drawback is you have to manually check for email, which I don't mind doing if it's going to save my battery life.
Vin, brotha...would you please consider tossing this program into your next ROM? It's very small...
for the record: I didn't write this program, and don't remember who the author is. But props ...