Exchange 2013 Logon Error: From Guide
If when opening the Add2Exchange Console you get a fail to log in, there are several causes:
• Incorrect password
• Incorrect format of service account: Must be SMTP email address such as zAdd2Exchange@domain.com
• Server name should be netbios name or name of exchange server dag or cluster
In some environments a new DNS entry must be made for internal autodiscover to resolve this. Autodiscover may be set up external and Errors such as these in the Add2Exchange Event log will manifest:
Domain/autodiscover/autodiscover.xml: ERROR_WINHTTP_NAME_NOT_RESOLVED (MAPI_E_CALL_FAILED)
To resolve this failure to log in for 2013, you must add a new Host A record entry in DNS in the forward lookup zone which points your external www-mail hostname to the internal IP address of the server or load balancer.