I am on London as well, and had to perform some tweaks Adam's original code (very clever stuff) to get this work. When I migrate to "New York" i'll make sure to address this business rule after the upgrade.

The main idea here, was to convert the code to use the 'sys_attachment' table as opposed to the 'sys_email_attachment' table.

(function executeRule(current, previous /*null when async*/) {

	var logs = ['Inline Image Email'];
	if(current.body.indexOf('[embedded report]') == -1) 
	{ 
		// if not found, leave everything alone 
		return; 
	} 
	
	// get email attachments and set them to inline attachments 
	var attach = new GlideRecord('sys_attachment'); 
	attach.addQuery('table_sys_id', current.sys_id); 
	attach.addQuery('table_name', 'sys_email'); 
	attach.addQuery('content_type', 'STARTSWITH','image/'); // only images supported 
	// set any attachments as being inline so they aren't attached 
	//attach.setValue('content_disposition', 'inline'); 
	attach.updateMultiple(); 
	// get the attachments to loop over 
	attach.query(); 
	// if  
	if(attach.getRowCount() == 0) 
	{ 
		logs.push('No attachments, so nothing to inline'); 
		current.body = current.body.replace('[embedded report]', 'Nothing to attach'); 
		return; 
	} 
	var reportContent = ''; 
	// add tags to inline all the images 
	while(attach.next()) 
	{ 
		
		reportContent += '<img src="{filename}"/>'
			.replace('{filename}', attach.file_name); 
	} 
	// replace the tag in quotes since that can't have tags added to it.  This should be a smarter regex, but we'll brute force it for now 
	current.body = current.body.replace('\'[embedded report]\'', ''); 
	current.body = current.body.replace('"[embedded report]"', ''); 
	// add the image tags 
	current.body = current.body.replace('[embedded report]', reportContent); 

	gs.info(logs.join('\n'));
	return; 






})(current, previous);