Andrew,

I don't quite know what you mean by me not needing either query, I'm still new to apex so I'm open to any suggestion on another way to do this.   If multiple emails cause one invocation of my trigger I just want the most recent email created date to populate into a field on the associated case.  I think the only ways that a new Email Message is created is by Email2Case, through the UI, or through an import into the application.

Here is the trigger code on Case Age in Business Hours. There are 3 select queries, two are in for loops.

trigger CalculateBusinessHoursAges on Case (before insert, before update) {
if (Trigger.isInsert) {
for (Case updatedCase:System.Trigger.new) {
updatedCase.Last_Status_Change__c = System.now();
updatedCase.Time_With_Customer__c = 0;
updatedCase.Time_With_Support__c = 0;
}
} else {
//Get the stop statuses
Set<String> stopStatusSet = new Set<String>();
for (Stop_Status__c stopStatus:[Select Name From Stop_Status__c]) {
stopStatusSet.add(stopStatus.Name);
}

//Get the default business hours (we might need it)
BusinessHours defaultHours = [select Id from BusinessHours where IsDefault=true];

//Get the closed statuses (because at the point of this trigger Case.IsClosed won't be set yet)
Set<String> closedStatusSet = new Set<String>();
for (CaseStatus status:[Select MasterLabel From CaseStatus where IsClosed=true]) {
closedStatusSet.add(status.MasterLabel);
}

//For any case where the status is changed, recalc the business hours in the buckets
for (Case updatedCase:System.Trigger.new) {
Case oldCase = System.Trigger.oldMap.get(updatedCase.Id);

if (oldCase.Status!=updatedCase.Status && updatedCase.Last_Status_Change__c!=null) {
//OK, the status has changed
if (!oldCase.IsClosed) {
//We only update the buckets for open cases

//On the off-chance that the business hours on the case are null, use the default ones instead
Id hoursToUse = updatedCase.BusinessHoursId!=null?updatedCase.BusinessHoursId:defaultHours.Id;

//The diff method comes back in milliseconds, so we divide by 3600000 to get hours.
Double timeSinceLastStatus = BusinessHours.diff(hoursToUse, updatedCase.Last_Status_Change__c, System.now())/3600000.0;
System.debug(timeSinceLastStatus);

//We decide which bucket to add it to based on whether it was in a stop status before
if (stopStatusSet.contains(oldCase.Status)) {
updatedCase.Time_With_Customer__c += timeSinceLastStatus;
} else {
updatedCase.Time_With_Support__c += timeSinceLastStatus;
}

if (closedStatusSet.contains(updatedCase.Status)) {
updatedCase.Case_Age_In_Business_Hours__c = updatedCase.Time_With_Customer__c + updatedCase.Time_With_Support__c;
}
}

updatedCase.Last_Status_Change__c = System.now();
}
}
}
}

 Thanks,

Christian