Hi,
This error is received basically due to incorrect service account and credentials in your setting for the Email Router as well as incorrect privileges for that account.
I would suggest to go through the below link provided by microsoft to have a good understanding of using different options of configuring the Email Router. Although it is lengthy, but still it gives good information about what options/ways should be selected
under what circumstances.
http://technet.microsoft.com/en-us/library/hh699786.aspx
Also, the following link provides different scenarios to handle the email router problems:
http://www.microsoft.com/en-us/download/details.aspx?id=21445
In addition to this, I would also suggest in case you are using the exchange services then proper access needs to be given at the exchange/domain servers also without which even though your email router configuration is correct but it will not authenticate
at the exchange/domain servers.
Let me know in case you find any difficulty after going through the links provided above and that of Mahender.
Thanks,
