Get a list of mail not sent in a campaign

I had problems in completing a campaign . Now , I can see the number of sent email ( 50% of the total) , the list of those who have viewed and clicked on the email ( 20% ) , but I can not find information about the mail sent , so as to perform a selective transmission . I made a query in the log table ( mysql ) , looking for errors . And I found them . SMTP connection failure . I then got a query all emails related to that error , during the period of the campaign . The problem is that this error is related to all email campaign , then some have been properly sent , but I can not figure out what . phplist sends email via an SMTP relay server . Thanks , Gianmario .

@JSalvo1978 If you requeue the campaign then it will be sent only to those whom it was not originally sent.