SOME emails to my custom domain address are not arriving. 

Today specifically an email was sent and never arrived. It was cc'd to my home address and that arrived fine.

I have checked the safe senders list and the domain name is on it. It is also not on my blocked list. I have done a search of all folders to look for the message too, but it isn't there.

Can anyone in support check for me and trace why some emails are not arriving?