This post shows how to save the MailItem that is sent. Saving with the a timestamp that matches when it was sent would be a little challenging, but if you use this method you will save with the timestamp of when it was received.
Sorry Harish, I misunderstood your question. The same response applies however. If you notice in the previous post you can find the MailItem by accessing the OutlookMail property of the email your are sending using the MicrosoftOutlookMail component. This is the actual email. Use the method listed to save it (see other post for more details). It would look something like this (with the steps for setting up the email missing of course).