After old daylight savings time adjustment email times are off 1 h

We didn't adjust our time with the new daylight savings date, but instead
went 3 weeks off 1 hour. We are on NT4 and Microsoft Exchange. When the old
daylight savings date occurred our times adjusted correctly but now our email
messages are showing 1 hour later.

If we go into the calendar options under time zone the time was showing 1
hour late, so we unchecked the daylight savings box. Our emails now looked
correct but this modified all our calendar entries which were correct to be
one hour early and it also changed my PC's time.

Is there a way to correct everyone's email timestamps without affecting
everyone's calendars? How can we most easily recover from this?

Thanks
Terrie