We are sending correspondences to end user for further information and waiting for user response, SLA starts after correspondence triggered.

• In some scenario’s “Customer email Id” will be the wrong and in this case “Fix Correspondence” will happen to Fix correspondence wrong email id.
• “SendEmailMessage” OOTB function will validate the email id and returns “invalid Address” if it is not valid But it is not validating whether email id is exist or not. Case is routed to next assignment and SLA starts in.

So We are facing SLA breach issues if email is not triggered to customer if it is not exist. Can you provide any info to overcome this issue.