Sonicwall TZ300 Blocking Outbound SMTP
Our tz300 is suddenly blocking outbound smtp port for 25, 587 and 465. Default config and policies are setup and nothing has changed with the Sonicwall or the ISP connection. I’m certain that the default behavior is for all outbound ports to be open. As a test, I have disabled all security features. Kinda stumped by why these smtp ports are no longer connecting, which is preventing Outlook from sending emails. If I connect directly to the ISP device, I am able to use smtp, so I’m certain the Sonicwall is blocking outbound smtp traffic.
Any suggestions or advice is appreciated.