There's no way to tell you definitively because you give no details. Tell
me, if your automobile had a problem, would you say to the mechanic "my car
doesn't work" and expect an intelligent diagnosis? Of course not. Don't
expect one here, either, without describing your Outlook version, what type
f account you have, and wehat your EXACT symptoms are, including what
changed on your PC between the last time things were working and now and
also what you did during that interval.
