In addition to Nikki's suggestion, you can also check the option to
automatically decline conflicting meetings (Tools-Options-Calendar
Options-Planner Options.)

--
Milly Staples [MVP - Outlook]

Post all replies to the group to keep the discussion intact. All
unsolicited mail sent to my personal account will be deleted without
reading.

After furious head scratching, Rossingol asked:

| Meeting requests are accepted automatically when email is opened by
| the invited attendee and then double booked when the user
| accepts the meeting. I have tried unchecking the box in the tools,
| options, . . . resource and tried turning off auto preview of message
| thinking that was somehow forcing
| acceptance. I am stuck and can't quite figure it out. Please your
| comments are very much appreciated.