Can't send emails from internal devices to external host

  • Notifications from my pfsense box work, but anything on the inside of my network won't send to my email hosting.

    I can use Outlook to access my email using imap and smtp fine, but anything on the inside of the network trying to send to my host is not working.

    I have a QNAP NAS that has worked previously but not now. I also have another network software controller that cannot send emails.

    Firstly I did find that Suricata was blocking the traffic but I corrected that, I can see the packets in the firewall establish the connection with the email host, but does not send the email.

    Performed a Packet Capture however I have no idea on how to read it.

    My email is hosted by a webhost using cPanel, the smtp port is 465 with SSL/TLS

    Any suggestions?