I’m moving my websites to two new servers and so I’ve installed Virtualmin on both of them. I used Proxmox Virtualization software to create two installations of Ubuntu 24.04
Everything about them is the same. The email on one of them is working GREAT! On the other one it seems to have intermittent connectivity issues.
The email worked well when I first installed everything and after creating a few websites it’s having problems connecting to Outlook or Thunderbird or any email viewer outside of the website.
I installed roundcube and it works with no problem. I can also view the mail through Usermin with no problem. I just can’t connect the IMAP
I can connect SMTP but only on port 25 rather than 587.
I’ve checked to see if the ports are in the firewall and everything is fine there.
Yes, but which firewall? Virtualmin’s firewall is pre-configured for mail, so it cannot be a cause for the problem. By default, the Proxmox VE firewall allows access to the web interface (port 8006), SSH (port 22), and SPICE proxy (port 3128) from the local network, but blocks all other traffic. Additionally, your service provider might have its own firewall which can be configured through their control panel.
It seems to me that there is a firewall somewhere that has port 25 open but not 587 and 465 or 993.
Fail2ban has not been running. I did activate it this morning to see if that has an effect. How would you suggest I fix the firewall issue? I certainly don’t want to run the website without it!
I’m glad you brought up all that information about Proxmox! I’m really new at that software as I’ve used VMware previously.
I used Proxmox because it was free and people online said that it used less of the server’s resources than did VMware. Plus VMware doesn’t work with older hardware.
In any case I had seen that there is a datacenter firewall, a server firewall and a firewall for each instance. So there are three levels. Since I’m using an IP address that is different from the Proxmox access IP then I need to look at the server firewall which seems to control all the servers.
That firewall doesn’t seem to be blocking anything but I turned it off anyway to be sure.
The firewall on the instance is also turned off.
The ports were still blocked!
So I restarted the firewall on Virtualmin a couple times and then I went in and specifically configured post 587 and port 993 as individual ports to be open to the firewall and I think that did the trick!
So in order to have my email browser connect to the Virtualmin instance I completely turned off the firewall then I was able to connect my email browser. After it was connected I turned the firewall back on and my email browser still seemed to be connected as I’m receiving email!
Since I have four other server instances configured within this Proxmox installation and they are having no problems connecting to email or web servers I really believe the issue is indeed the firewall in Virtualmin. But If I’ve solved the problem by tinkering around then GREAT!!! I’m still not sure what I did to make it work… but I’m glad it does.
The Proxmox datacenter firewall is now back on… the server firewall is on and the individual instance firewall is off. On the instance level I’m depending on the Virtualmin firewall. Everything seems to be working now and I just ran an external port scan which does show that all the correct exposed ports are open!
This is a lot more complicated than just setting up a regular Virtualmin website!!! I think it will be worth it in the end as this offers me a ton of flexibility with the overall configuration.
Thanks for your feedback! After working with this for days trying to get everything to work it’s easy to get confused and forget what I did and didn’t do… PLUS someone like you is always bringing up points to consider that I never even knew existed!!!
I’m glad you brought up all that information about Proxmox! I’m really new at that software as I’ve used VMware previously.
I used Proxmox because it was free and people online said that it used less of the server’s resources than did VMware. Plus VMware doesn’t work with older hardware.
In any case I had seen that there is a datacenter firewall, a server firewall and a firewall for each instance. So there are three levels. Since I’m using an IP address that is different from the Proxmox access IP then I need to look at the server firewall which seems to control all the servers.
That firewall doesn’t seem to be blocking anything but I turned it off anyway to be sure.
The firewall on the instance is also turned off.
The ports were still blocked!
So I restarted the firewall on Virtualmin a couple times and then I went in and specifically configured post 587 and port 993 as individual ports to be open to the firewall and I think that did the trick!
So in order to have my email browser connect to the Virtualmin instance I completely turned off the firewall then I was able to connect my email browser. After it was connected I turned the firewall back on and my email browser still seemed to be connected as I’m receiving email!
Since I have four other server instances configured within this Proxmox installation and they are having no problems connecting to email or web servers I really believe the issue is indeed the firewall in Virtualmin. But If I’ve solved the problem by tinkering around then GREAT!!! I’m still not sure what I did to make it work… but I’m glad it does.
The Proxmox datacenter firewall is now back on… the server firewall
