I'm having a hard time trying to setup an SMTP relay to my local server which cannot be addressed directly because ISPs are constantly blocking port 25 over and over and then it takes forever for them to open it back up; I've followed all the help on the wikis for Webmin and Virtualmin but everything is so ambiguous I'm not a 100% sure when I'm doing one thing I'm doing the opposite in some other place; I've tried using Postfix and Sendmail and can't get anywhere.
I have a Webmin instance on a rented host online that's supposed to accept everything and relay it to our domains but I keep sending test emails and watching the firewall for incoming comms from Webmin's IP address and there's zero but then again I can't shake the feeling that the places so far where I've told Webmin where to relay the email to aren't quite right and I'm afraid of going too deep and linking it with LDAP because I'm in an AD environment and I really can't mess that up.
Outgoing email was easy, I'm just using Mailgun; incoming via Mailgun goes into APIs and whatnot, so it's not an option. That led me here; do you guys know of a step-by-step guide on how to achieve this? A link or PDF, or a clue you'd like to share, anything is good. <3
I do have the license for Virtualmin BTW but since they're basically the same I haven't converted it until I get this working. I guess if I run out of options I'll try setting up a cloud router using pfSense and just NAT the ports and un-NAT them the local edge...anyway,
Thanks for your advice!