CRM 2011: Email Router configuration error – “Incoming Status Failure: No results were found”

Error:  

Email Router configuration error "Incoming Status Failure: No results were found"

Solution:

If you dig around you will find out that this error is actually coming from Microsoft Exchange.

In our case, the error coming from Exchange was "ErrorCode=ErrorNameResolutionNoResults" 

and according to MSDN Exchange ESW reference
"This error indicates that the ResolveNames operation returns no results."

Consider the following to resolve the issue

• Make sure email addresses are available in Exchange's Global Address List (GAL)
• Make sure mailbox is not hidden from exchange address list (checkbox)
• Make sure all accounts are in PrivUserGroup
• Make sure Exchange webservice is accessible from the CRM server
• Make sure the account's mailbox is not over-limit
• While configuring incoming profile enter credentials as 
• domain\user (not user@domain.com)

If you are using a service account to access the mailboxes of other CRM users and/or queues then check the following

• Make sure service account's email address is available in Exchange's Global Address List (GAL)
• Make sure service account has full rights on the mailboxes.
• Adding a Management Scope for the service account to impersonate other users.

For us, this issue was resolved by creating a mailbox for the service account and exposing it to the Global Address List (GAL). You may be able to resolve this issue without creating a mailbox for the service account but it must not be hidden from the GAL.