When a customer enters their contact information to be added to my Mailing List on my web site, Is there a way this just gets entered into Nexternal rather than me having to import it into Nexternal?
Yes, you can automatically push that data into Nexternal if the form on your website is properly coded to do so. You (or a programmer) may use the instructions provided in our Customer Integration documentation, available here http://www.nexternal.com/documentation/customers.htm. Some html form coding knowledge is necessary. There are also a few settings to configure in your OMS in Customers / Integration.