I have a fresh install of Virtualmin using the install script. I am running Ubuntu 20.04. Everything seems to be working except for Postfix/SMTP. I can receive mail, just can’t send it. I have confirmed the service is running, tried both secure and non-secure ports, even tried a custom port. I can’t even send a message via Usermin. I receive an error stating “ Failed to send mail: SMTP command failed”
I’ve searched the web high and low on how to fix this, but now i’m at a loss. Any help is appreciated!
Yes, I have a Let’s Encrypt cert installed.
Also, here is nmap from another host. I have removed my IP and Host:
nmap MYDOMAIN
Starting Nmap 7.80 ( https://nmap.org ) at 2021-07-15 19:43 UTC
Nmap scan report for MYDOMAIN (IP)
Host is up (0.00048s latency).
rDNS record for ----
Not shown: 988 closed ports
PORT STATE SERVICE
25/tcp open smtp
80/tcp open http
443/tcp open https
465/tcp open smtps
587/tcp open submission
993/tcp open imaps
6789/tcp open ibm-db2-admin
7443/tcp open oracleas-https
8080/tcp open http-proxy
8443/tcp open https-alt
8888/tcp open sun-answerbook
9090/tcp open zeus-admin
Nmap done: 1 IP address (1 host up) scanned in 0.21 seconds
On the domain you’re working on. Go to Server Configuration/SSL Certificate/Service Certificate and copy all certificates. Also do the same for your main server domain. That might work.