What is the default SMTP server on Proxmox 6?

[gibus]

Hello,

I introduce myself to this forum; I am a user of the wonderful Proxmox, since few months. It is just a hobby for me, I am not a power user. Before using Proxmox, I was a Debian's user with hosting personal servers (Apache, Nextcloud, multimedia, ...). All servers where on a single Debian OS. Instead of using a single OS (Debian 10) with virtual machines (like Virtual Box), last year I choose to install the Proxmox OS. I first installed the Proxmox OS over my Debain OS. Everything worked perfectly. After the last release of Proxmox (6.1), I choose too install it on a empty new SSD. The Promox OS (iso image 6.1) works well, and I am installing all VM that are hosting my server (Apache, Nextcloud, multimedia, ...)

I have a question about the mail status that is nightly send "my" new Proxmox OS. During the installation, I set an email. This email is used to receive status of the Proxmox. But during the installation, I never have set a SMTP server to send the email. Every nights, I receive an email about a smart error on my HDD.

My questions are: What is the default SMTP server? From which server my mails are send? Where the configuration is stored? Can we change this configuration in the interface? Or does this configuration only available in command line?

Thanks in advance.
Best Regards

 

[aaron]

AFAIK Proxmox VE sends the emails directly to the email server set in the MX record of the domain of your email address.

There are infos in this forum and on the internet how to configure the underlying postfix email server to use a relayhost (sometime with authentication).

But if you get the emails why would you want to manually specify a relayhost?

 

[gibus]

OK, thanks for the reply. From my point of view and for safety reason, it is advise to have a login/password on a SMTP (or Postfix, not sure !?!) server to avoid spam and so on ... Moreover, if everybody can set a mail server without any authentication, the web will be a disastrous place with spam!
I was just surprise to receive an email without any configuration set on my side . I just want to understand the behavior of the software I install ;-). Any help for my understanding is appreciate

(Note: I am not a mail admin, nor a network expert )

 

[aaron]

Having authentication for a mail server is needed if it relays emails from other clients. Since the postfix installed on PVE will only send emails from the local system this should not be an issue.

Everyone can open a connection on port 25 (SMTP) on your receiving mail server and send you an email. Depending on how strict the spam filtering is you can even do it manually with telnet or netcat.