I have a few clients hosted on my servers and I relay on Amazon SES to send emails. This information is relevant because all the emails that use Amazon service wont receive the response from Xerox with their Xerox Workplace Cloud account. Other accounts that send directly from my server will receive everything and I can use it to print just fine.
I know that the emails are sent but the response never arrives.
EDIT: The emails are sent from eu-west-1.amazonses.com (Ireland)