http://mscrmuk.blogspot.com.au/2012/04/crm-email-router-errors-with-adfs.html

1. Use regedit to go to the HKLM\System\CurrentControlSet\Services\MSCRMEmail key
2. Add a Multi-string (REG_MULTI_SZ) value 'DependOnService'
3. Set the value to adfssrv (or add this value if there were already a dependency)