Dynamics CRM 2016 on-premise Record Creation and Update Rule

Hi Team,

have anyone experienced Record Creation and Update Rule issue

My issue:

i created more than 10 email Rule for incoming mail for helpdesk

that will create a case and queue then send mail to helpdesk

however, the mails syn into crm from gmail and cases are created regarding to the mail

but my issue is that....some of the mails are in Crm mail but doesn't create case 

Any idea for the root of this 

Thanks