I accepted a meeting request with a phone number on it, assuming that I would be able to open that message again in the future to get the number. But when I went back to my Inbox right before the meeting, the message was gone.
I was ultimately able to find the message in my Deleted Items folder, which is not preferable if you have configured Outlook to empty your Deleted Items folder upon exit.
Step 1: Launch Microsoft Outlook 2010.
Step 2: Click the File tab at the top-left corner of the window.
Step 3: Click Options at the bottom of the left column.
Step 4: Click Mail in the column at the left side of the Outlook Options window.
Step 5: Scroll to the Send Messages section at the center of the window.
Step 6: Click the box to the left of Delete meeting requests and notifications from Inbox after responding.
Step 7: Click the OK button at the bottom of the window.
MCTSC | Exchange Server