GudenSoft is email application or email program for windows mobile that let you manage your email send scheduler throught POP and IMAP. For example, why waste resources downloading messages if you’re sleeping? Or say you want to schedule regular intervals during work hours for one account, but want a less frequent download schedule while at home. This email scheduler will do just that and it makes email scheduling more practical.

There has been a complete rewrite and a laundry list of fixes/changes since we last reported about this scheduler, so be sure to visit the developer’s site and forum.

source at xda developer forum and developer site