Problem with anonimous relay

[scea]

Hi,
I have a problem with my proxmox configuration and i have read the forum without finding a solution.

The thing is that the current configuration allows the sending of spam from within the SMTP of proxmox.

Actually the smtp allows to do something like (i have changed the domain names for the example):

220 proxmox.myproxmoxinstalleddomain.com ESMTP Proxmox
EHLO WW
250-proxmox.myproxmoxinstalleddomain.com
250-PIPELINING
250-SIZE 10485760
250-VRFY
250-ETRN
250 8BITMIME
EHLO www.proxmox.com
250-proxmox.myproxmoxinstalleddomain.com
250-PIPELINING
250-SIZE 10485760
250-VRFY
250-ETRN
250 8BITMIME
MAIL FROM: someone@gmail.com
250 Ok
RCPT TO: scea@myproxmoxinstalleddomain.com
250 Ok

DATA
354 End data with <CR><LF>.<CR><LF>
asd
.
250 Ok: queued as CA5508088E

quit
221 Bye


Or even worst putting in the MAIL FROM: someuser@myproxmoxinstalleddomain.com

What do i have to change to avoid this situation?

Thanks in advance.

(sorry for my bad command of english)

 

[tom]

Hi,
I have a problem with my proxmox configuration and i have read the forum without finding a solution.

The thing is that the current configuration allows the sending of spam from within the SMTP of proxmox.

Actually the smtp allows to do something like (i have changed the domain names for the example):

220 proxmox.myproxmoxinstalleddomain.com ESMTP Proxmox
EHLO WW
250-proxmox.myproxmoxinstalleddomain.com
250-PIPELINING
250-SIZE 10485760
250-VRFY
250-ETRN
250 8BITMIME
EHLO www.proxmox.com
250-proxmox.myproxmoxinstalleddomain.com
250-PIPELINING
250-SIZE 10485760
250-VRFY
250-ETRN
250 8BITMIME
MAIL FROM: someone@gmail.com
250 Ok
RCPT TO: scea@myproxmoxinstalleddomain.com
250 Ok

DATA
354 End data with <CR><LF>.<CR><LF>
asd
.
250 Ok: queued as CA5508088E

quit
221 Bye


Or even worst putting in the MAIL FROM: someuser@myproxmoxinstalleddomain.com

What do i have to change to avoid this situation?

Thanks in advance.

(sorry for my bad command of english)

Hi,

just for clarification: your are talking about incoming emails (internet > proxmox) or outgoing (LAN > proxmox > internet)?

 

[scea]

From outside the internal lan:

telnet proxmox.myproxmoxinstalleddomain.com 25

and do the described steps

i know with procmail you can do something like
[FONT=&quot]:0H
* 1^0 ^From: .*@mydomain.com
* 1^0 ^Return-Path: .*@mydomain.com
* ! Received: from .*163.247.58
{
:0:
/tmp/SPAM
}[/FONT]

to control the valid ips to send from my domain but i dont know if that can be implemented in proxmox
Thx for answer.

 

[tom]

From outside the internal lan:

telnet proxmox.myproxmoxinstalleddomain.com 25

and do the described steps

i know with procmail you can do something like
[FONT=&quot]:0H
* 1^0 ^From: .*@mydomain.com
* 1^0 ^Return-Path: .*@mydomain.com
* ! Received: from .*163.247.58
{
:0:
/tmp/SPAM
}[/FONT]

to control the valid ips to send from my domain but i dont know if that can be implemented in proxmox
Thx for answer.

Hi,

Please define a valid SPF record for your domain and activate SPF on your Proxmox. For details about SPF, see http://www.openspf.org/

Proxmox will accept most emails via telnet (except you are sending from a blacklisted IP or SPF fails, if activated) and analyze it after. Proxmox is doing most spam analysis after the queue.