ChaRM - Rfc Approval procedure Workflow shows error status

Hi All,

After the Rfc approval procedure work flow setting in SPRO, getting the below error. mail is not triggering from Approval workflow.

Also i checked the below link, but i am not able to find the figure out the exact issue.

http://scn.sap.com/community/it-management/alm/solution-manager/blog/2013/10/31/new-charm-feature-with-sp-10-enhanced-approval-procedure-functions

ChaRM: Approval Settings - Email Functionality in Change Request

In So01-> outbox  shows error in the status

I cross checked all the setting , but Rfc approval worflow is not coming to inbox. Still it showing error in outbox status.

Rg,

Karthik