[apere006]

If you have mail set to fetch new data at any interval, except manual, it will always be running in the background. For me uses at least 11 mb in addition to the processor cycles it always using. I find this very wasteful but I can't have it never checking for mail. I think it would be useful if there was small mobile substrate app that you could set to fetch new mail every x minutes, so you can have your email set to manual and not running in the background. A daemon could also be used if it only opened itself every x minutes and then shut down.

[apere006]

At least for me 11 mb is about 50% my available memory. 50% more memory could mean less crashes and with the reduced processor load more battery.
I don't know but could this be done with a .plist file in LaunchDaemons folder? I remember nemussync used to be able to auto update every XX minutes using this .plist http://www.nemustech.com/iPhone/com.paf78.autoNS.plist