We have Exchange 2003 running on SBS 2003. Recently a lot of emails have started to be blocked by other ISP's. We have been getting messages back stating our IP address is on a block list.
I contacted our web/domain host and they claim that since we are running exchange, the email are actually sent from our server, and not the hosting server.
Is this correct?
I thought that exchange passes the email through to the webhost via an smtp connector. I presumed email still got sent like normal email at the end of the day.
Is it possible that our exchange server is sending email directly?
If so, what is the cause of being on a block list, it is our server IP address or the IP address of our local ISP?