It is possible to insert a Send to a Friend Link into your email so that a recipient may send their friend/colleague a copy of this email.
Under the Advanced Details section in your Campaign Setup, you will find a field called 'Send to a Friend'.
Select the 'Send to a Friend' you created in the step before and attach it to the campaign from the drop down.
Once this has been done you are finished! The link will now work in the email.
Please Note: Make sure to test the link by sending yourself a test email in the Campaign Setup!