No email to fetch the cert

Hello,

I already have an email account with a certificate and it works as it should, but I want to secure another certificate for another account on the same domain as before.
As i fill in the request it shows success…but the email just does not arrive. And when I try to request for the same certificate again it says it has already issued a certificate for that email address. The certificate is neither in Firefox, nor is there any email in my inbox in Outlook nor in its junk folder. It has not even arrived on any of may servers which pass on the mail to me.
Any ideas, what is happening? Would appreciate a note to set me in the right direction.

Thanks