Question:

Is it possible to check the reason for Approved Emails with high bounce rates?

Answer:

Run the following query, paying attention to the last lines of the Event_Msg_vod__c field, to determine the reason for failure.

SELECT 
Activity_DateTime_vod__c,Event_Msg_vod__c,LastModifiedDate,Name,Sent_Email_vod__r.Status_vod__c,Sent_Email_vod__c
FROM Email_Activity_vod__c 
WHERE Sent_Email_vod__r.status_vod__c  in ('Dropped_vod','Bounced_vod')
AND Sent_Email_vod__r.Approved_Email_Template_vod__c = '<Approved Email Template ID>'
ORDER BY Activity_DateTime_vod__c ASC NULLS FIRST

Related Documentation:

CRM Help Documentation: Tracking Approved Email Activity