Over the past two days, two of our employees have tried sending an email to one of our clients and these emails are sitting in a Queued state and not being delivered. There are six emails to this client. Does this mean that our email server is not getting a response from the mail server at the clients domain? How can I test this or see if this client's email/domain is the problem or tell if the problem is our server? All other emails are going through just fine it seems, it's just these six emails. This is one of our bigger clients and my sales guys are not happy their emails aren't being sent and I am not sure what to tell them.