Whitelist an email address in Microsoft Exchange 365

We were presented with this issue at work by which notification from DocuSign were not reaching internal recipients, what could be wrong? Could it be that perhaps the automatic emails from DocuSignare somehow blocked on our Exchange online?

Trace Messages

First of all, you might want to verify the status of the emails, why have them been blocked. To do that visit Exchange Admin Center >> Mail Flow >> Message Trace. Once in there, you should use one of the default queries to start your search