there are 2 machines at this location. One of them (a 3635) scans fine and has no problems sending to internal and exteral email addresses. But the other (a 7755) will only scan to internal adddresses. Both machines have the exact same SMTP server information, login, and are both on the same network. I have even had the network administrator put the IP address of the 7755 in the smtp relay so i dont believe that is the issue
my question is, why is the one machine working correctly while the other is not?
In my experience this is usually because of an authentication issue. Many SMTP servers only require authentication when sending to external addresses. Recheck SMTP. Also, the board on the 3635 is significantly different than that on the 7755. It may require some different or additional settings to function correctly.
For this setting: "Login Credentials for the Walkup User to send Scanned E-mails:" Make sure that Same as Automated is selected. Also the Workcentre Email Address field on the 7755 may need to be the same as the authentication account. I would also try adding @YourDomain.com to the authenticating account if it isn't already there.