I am running a Discourse container with about 70.000 registered users as of today.
So using Mailgun to send all mail communication and digest becomes quite expensive atm.
There were sent about 500k mails within the last 30 days.
My dedicated server is running Ubuntu 16.04 with a solid ISPConfig3 installation. Mailserver etc. working just fine.
Can I disable Mailgun and run all mails from the local server? Or will I just fill up every blacklist with my domain?