Submission confirmation emails

We have had a few reports lately of confirmation emails not coming through to the mailbox of the user submitting the form.  We think it may be due to the number of emails being sent between Jotform and our system.  We have whitelisted what we can but do you have a specific IP address that deals with the sending of emails your side? so we can look into approving this and ensuring we don't hit a receipt limit

I checked your email address and there's no form on your account. Could you please share the form link and the email recipient that is not receiving the confirmation email?

Guide: https://www.jotform.com/help/401-Where-to-Find-My-Form-URL

We'll wait for your reply. Thank you.