I've recently taken on a client. They were running an SBS 2003 Server with exchange, on a dynamic IP. Emails coming through POPCon and going out through an SMTP connector.
They got hit with a SPAM attack, which I have cleared following the advice on here (thank you). I have organised and configured a static IP address, which is operational, and canyouseeme.org reports the relevants ports open and services working.
Now that emails flow directly to the server, they are not coming through. I can telnet locally (from the server) to port 25. But not externally. I know the service is operational, and the port is open.
I am looking for the next step please. The ultimate goal is for the emails to flow through a hosted spam filter before arriving at the server. But the service cannot be configured until emails are flowing properly.
Many thanks in advance for you help.