Create your mailing and when building your receiver base query, follow these steps:
- Expand the Communication folder and select eNewsletter Subscriber Lists and click Add
- Mark the radio button next to the eNewsletter subscriber base
- Then, select the Past Mailings criteria and click Add
- Mark the radio button next to the eNewsletter issue that you wish to "resend"
- Then, click the Not qualifier on Past Mailing item, so that you are filtering on people who did not receive the mailing
- Click the Preview button to see the list, if you like, then click Done