After the creation of a new task : Create “New task”

1- In Tabs => Click on  “Accounts”

2- In View Menus => Select “My Accounts”

3- In  ListViews => Click on “Account” ” YOUR ACCOUNT

Scroll down to the "Open Activities" related list and click in "New Task”

1- Click on the "Name" magnifier (Click on the lookup field. Write the name of the contact or the supplier you are searching. Choose "All Fields" in the "Search" requirements under the lookup window. Click "Go!“)
 

2- Tick box on the "Create a Supplier Action" little square box to engage the supplier in the process

Click on "Save"

Click on email Link

The supplier can modify the task by clicking on Edit

Select “Submitted” in view menu supplier status

Click on Save