I've reviewed the CSF.conf file and noticed all the ports are listed in TCP and TCP6 in/out. I noticed this section: SMTP_PORTS = "25". I've tried 465, 587 and still getting the message in XenForo "couldn't open socket".. I've restarted CSF as well. Any hints? Open Port Check Tool - Test Port Forwarding on Your Router tells me the port is closed as well.