Only one communication gets created in CRM when an email with three reciepients is sent. All three recipients are set up as Person Records in CRM.
Send out an email with 3 recipients. One of these will be the email address of a user of CRM.
The other two email addresses will be for people that are not in CRM.
Once the email is sent only one communication is created and In the database only 1 comm_link was created but there should have been 3 created for both.
This issue has been resolved in Sage CRM patch 7.1o.