It is normal to see messages in queue when a mailing is in progress. owever, if the message persists as you browse around ListMail then the mailing is not completing. I recommend that you hit the "Resume" button next to the entry in queue to see if the email can be delivered. If it can't, it's possible/probable that there is one email address on your list(s) having a problem that ListMail is not detecting correctly.
Regards