In order to change the From address for Deployment task notifications you need to modify the following line in the DeploymentService.exe.config file located in the Control Center\bin directory on your Deployment Service server:
<add key = ?NotificationEmailFromAddress? value = ??/>
Insert the email address you wish to use between the quotes after the value.
Example: <add key = ?NotificationEmailFromAddress? value = ?Joe.User@company.com?/>