I have started using Outlook as an IMAP client for GMail. Until now, I never delete email in GMail (using the web interface)... I always hit "Archive" which simply removes the mail from the GMail Inbox, but leaves it in the "All Mail" folder of GMail.
I'd like to do this same thing in Outlook... when I "delete" a mail, rather than delete it, I want to simply remove it from the Gmail Inbox. That way the email continues to be in Gmail and can be searched later.
P.S. Same thing for my iPhone when managing email from there as well.