Ok – I Am hosting a web application that needs the ability to send an email via SMTP. To that end, I created an SMTP virtual server within IIS on the same webserver. Now the app sends emails perfectly. However, some domains drop the SMTP connection or refuse the email because the external IP address does not match the hostname with the receiver performs a Reverse DNS lookup. I have attempted a number of things to fix this, but to no avail. Rather than list those things here and possibly confuse the issue, can someone step me through what it is I would do if I were setting this up from scratch?
