I assume that the title speaks for itself. Current status is that by using the Office365.SendEmail function it instantly will send the mail. Especially experimenting with business applications combined with real customer data is very dangerous (I almost send a test mail to a supplier because I thought the function will be the same as mailto:)
What we want is the same functionality as the mailto-call (OnSelect = open outlook window for reviewing). Or you should give at least the option to choose if one want to send the mail instantly or first opening the mail client.
Clicking the "Send"-Button is not a significant time-waster.