You might notice that BBIS email messages that show as not being sent in the email report still show up in the Communications tab of the recipient's constituent record.
Download and install the latest patch which contains all fixes from previous patches. If you are running an older version, download and install the latest version and then the patch.
Steps to Duplicate
1) In BBIS go to Email > Messages > View report 2) Open the Not sent section of the report 3) In CRM search for the constituent records associated with the email addresses shown in the Not sent report 4) On the constituent record go to the Communications tab > Communications subtab 5) Notice that the email message is shown on the data list even though the message wasn't sent.