Cannot send mail

I am running ADSelfService Plus on a Windows 7 machine. I have an SMTP server in house and I can telnet to port 25 on that server (Windows 2012) from the Windows 7 command line, however, I cannot send mail from the application. I have other applications on that system that are able to send mail. It tells me that is cannot connect to port 25 on that server. Any ideas?