Intalled ENewsletter plugin. Using SMTP. Have verified SMTP

Intalled ENewsletter plugin. Using SMTP. Have verified SMTP is working. I can sent a test message no problem. When I send out the mass mail to the group, it hangs. I am using my own smtp server on the save machine as my wordpress. Here is one thing I am seeing in the apache error log. [error] [client XX.XXX.XX.XX] WordPress database error Incorrect integer value: '' for column 'end_time' at row 1 for query INSERT INTO hm_enewsletter_send SET newsletter_id = 16, start_time = 1393182191, end_time = '', email_body =""
I left out the the email body for space sake. Any ideas?