Error on Bursting report

[cognos05]

Hi ,

I am using 2 reports. One report I am able to burst and second report throws below error
We were unable to send a message to one or more recipients. Please contact your administrator.
Subject: Send failed: Report: Sample4
Date: Thu, Feb 5, 2015 05:06:34 EST
Error Message: CNC-SDS-0335 Error returned from SMTP Server. The error message was: [Invalid Addresses]. The message could not be sent.

Email Id used in both the reports are same.

I have a simple cross tab with two columns and a list with burst key and EmailID.

Any ideas on why the second report is giving smtp server error. both the reports are present in same folder.

Thanks,
Nithya