How to stop Inbound mails creating a case for Email Delivery Failure Notifications?

Hi Vijay

There are options either to adjust the OOTB behavior or just delete undesired case records created by setting deleted=1
If you consider the second option, you may do both - describe the logic of the identification of "undesired" case and set the Case.Deleted=1 with Logic Builder for Sugar

Btw, you may use OOTB Sugar SNIP service - just forward all the inbound emails to the SNIP mailbox and to create leads records instead of cases whenever those emails are archived with SNIP
I suppose Leads might have better served to Sell purposes than Case module, originally designed for Support (Cases are available in Sugar Serve)

All the Best,
Dmytro

We had a similar situation and we had to modify the code to achieve this, which is non upgrade safe - so this can be done only in a on-premise installation. There are several ways to do this via code, but we choose a simple approach instead.

Keep a list of standard subject templates that the email starts with. These can be preg patterns and can be stored in config to ensure they can be added/modified as needed:

Eg:

$sugar_config['email_subjects_to_skip'] =
    [
        "^Mail delivery failed",
        "^Delivery Status Notification",
        "^Out of Office",
    ];

Then in InboundEmail.php - handleAutoResponse (or handleCreateCase if you also want to stop creating cases for such emails), you can add a simple check that checks if the subject starts with one of these (don't check if the subject contains the string - because that could be a real reply or forward), and if it matches, just stop processing them and add helpful logs.

foreach($emailSubjectsToSkip as $skip) {
    if(preg_match("/$skip/i", $subject)) {
        $GLOBALS['log']->debug("Email with Subject $subject skipped...");
        return false;
    }
}

To make Neeraja's suggestion as upgrade safe. Please follow the below steps.

Extending the InboundEmail.php to custom path custom/modules/InboundEmail/InboundEmail.php

require_once('modules/InboundEmail/InboundEmail.php');
require_once('modules/ACLRoles/ACLRole.php');
require_once('data/BeanFactory.php');

class CustomInboundEmail extends InboundEmail{

//extend your desired function

}

and also add the below code in custom/Extension/application/Ext/Include/CustomInboundEmail.php

<?php

$objectList['InboundEmail'] = 'InboundEmail';
$beanList['InboundEmail'] = 'CustomInboundEmail';
$beanFiles['CustomInboundEmail'] = 'custom/modules/InboundEmail/InboundEmail.php';

Hope this helps you.