Often, we need to send only the latest attachment via email. However, using the "Include attachment" checkbox in notifications sends all attachments, making it impossible to send just the latest or a specific attachment.

To address this, follow these steps:

1) Create business rule which is After Insert on sys_email with correct condition for table name

2) Use the below script to pick latest attachment

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

    var s_Attach = new GlideRecord('sys_attachment');
    s_Attach.addEncodedQuery('table_sys_id=' + current.instance);
    s_Attach.orderByDesc('sys_created_on');
    s_Attach.setLimit(1);
    s_Attach.query();
    if(s_Attach.next()){
        var rec = new GlideRecord('sys_email_attachment');
        rec.initialize();
        rec.attachment = s_Attach.sys_id;
        rec.file_name = s_Attach.file_name;
        rec.source = 'notification';
        rec.content_disposition = 'attachment';
        rec.email = current.sys_id;
        rec.insert();
    }

})(current, previous);