1) Go to system -> configuration and click on the option  “contacts” (sidebar menu)  under the main category “general”  and check the “Email sender ” value that  is selected from the drop down . Let it be “Custom Email 2”

2) Go to system -> configuration and click on the option  “Store Email addresses” (sidebar menu)  under the main category
“general  . Then fill fields under the tab “Custom Email 2”  and save the data .