Today we replaced an old Instagate Ex with a new Sonicwall TZ-190 and we are having problems receiving E-mails. We are currently running an exchange server on SBS 2003 and everything such as OWA or surfing the Internet works just fine.
When setting up the Sonicwall I used the Wizard to create a public server on port 25 that was supposed to move traffice from the WAN to the exchange server, however only sending is working. I can telnet to the SMTP server inside the domain, just not through the Sonicwall. When I try telnet through the sonicwall I get a flashing prompt and no error message.
Latest firmware has been pushed into the Sonicwall. Any ideas anyone?