Service request follow up

Hi,

When an agent creates ticket and save the service ticket and want to use email as followup activity there is no values found in the popup of followup activity.

i have maintainted all settings in customization.

1. Transaction used is Service Request and Outgoing E-mail.

2. Maintained Copy Control to Service Request and Outgoing Mail Transaction.

3. Maintained Channels for the both transaction.

Still i am unable to find email as followup through interaction center agent.