When you have the e-mail open you should be able to click on the Options
button on the toolbars. This will open a window labeled Message Options. In
this window you should see a section for Delivery options. In here you can
check "Do not deliver before" and you can select a date and time. This will
make the message stay in your Outbox until this time has been reached and
then it will be sent.
I hope this information is helpful.
Robert Findlay
Partner Technical Lead -- BizApps
Microsoft Technical Support for Platforms and Business Applications