Unable to force auth on smtp, server transformed as spam relay after 2 days online

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Service
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Unable to force auth on smtp, server transformed as spam relay after 2 days online

Post by Service »

Hello,
here is my little story (background) : I am a user a Zimbra since the v5, and my current server is on the latest v6. Because of old hardware, I didn't upgrade, but everything worked really well.
Now that I have invested in a new server, I tried v8 (8.0.4_GA_5737.FOSS) as a fresh new install (no upgrade).

As I have 2 domains, the old server is on 1 domain, and the new one on the second domain, I will do an alias later.
But now, here is the problem : within the last 2 days, it seems that spammers have found the new server, and I was stuck with a mail queue of 350000+ mails.
After searching a little, it seems that auth on smtp was not mandatory (tested on MX Lookup Tool - Check your DNS MX Records online - MxToolbox on both servers, old one is good, new one is said to be an open relay).
This was my network setting :
zmprov gas -v | grep MyNetwork

-> zimbraMtaMyNetworks: 127.0.0.0/8 192.168.0.0/24 [somes ipv6 settings was here too]
to make stop the mess, now it is setup like that :

zimbraMtaMyNetworks: 127.0.0.0/8 192.168.0.2/24
The problem is that now, I can't send email throught the new server from everywhere.
The auth settings are setup like that :
zmprov getServer xxxxx.me | grep Auth

zimbraMtaAuthEnabled: TRUE

zimbraMtaAuthHost: xxxxx.me

zimbraMtaAuthTarget: TRUE

zimbraMtaAuthURL: https://xxxxx.me:443/service/soap/

zimbraMtaSaslAuthEnable: yes

zimbraMtaTlsAuthOnly: TRUE

zimbraShareNotificationMtaAuthRequired: FALSE


I have a question : is it normal that zimbraMtaSaslAuthEnable changed from TRUE / FALSE setting to yes / no ??


I don't really know why the new server don't enforce the use of auth on smtp, but it is a big problem for me, as now my ip is banned.
Can someone please help me.
Best regards.
phoenix
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Unable to force auth on smtp, server transformed as spam relay after 2 days online

Post by phoenix »

[quote]After searching a little, it seems that auth on smtp was not mandatory[/QUOTE]If you're talking about port 25 then implementing that will stop you from receiving email.
[quote](tested on MX Lookup Tool - Check your DNS MX Records online - MxToolbox on both servers, old one is good, new one is said to be an open relay).[/QUOTE]If that's the case then you have either done something to make Zimbra an open relay or there's something wrong with your LAN configuration - a default install of Zimbra is not an open relay.
[quote]zmprov gas -v | grep MyNetwork

-> zimbraMtaMyNetworks: 127.0.0.0/8 192.168.0.0/24 [somes ipv6 settings was here too][/QUOTE]That's the default and allows all machines on your LAN to send mail without authentication.
[quote]to make stop the mess, now it is setup like that :

zimbraMtaMyNetworks: 127.0.0.0/8 192.168.0.2/24[/QUOTE]You've entered an incorrect value for the LAN IP & Subnet, what are you trying to do with this change?
[quote]The problem is that now, I can't send email throught the new server from everywhere.[/QUOTE]How are you actually trying to send mail? Are you using port 25 or the correct submission port 587?
Regards

Bill

Rspamd: A high performance spamassassin replacement

Per ardua ad astra
Service
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Posts: 1023
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Unable to force auth on smtp, server transformed as spam relay after 2 days online

Post by Service »

[quote user="10330phoenix"]You've entered an incorrect value for the LAN IP & Subnet, what are you trying to do with this change?[/QUOTE]
It was a quick fix to make it stop the problem. I know that it is not the way to do it.
But I thnik I found the problem, maybe you can confirm that for me.
Both servers are behind a router, ports for the old one are routed directly on the local ip of the server, but for the new one, ports are routed on a server that is iptable to forward everything to zimbra, so everything is seen as comming from the local network.


I will change the way ports are routed for the new zimbra.
Will come back to tell if it was that.
Thanks.
phoenix
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Unable to force auth on smtp, server transformed as spam relay after 2 days online

Post by phoenix »

[quote]Both servers are behind a router, ports for the old one are routed directly on the local ip of the server, but for the new one, ports are routed on a server that is iptable to forward everything to zimbra, so everything is seen as comming from the local network.[/QUOTE]Yes, that will make it an open relay.
Regards

Bill

Rspamd: A high performance spamassassin replacement

Per ardua ad astra
Service
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Posts: 1023
Joined: Tue Apr 14, 2009 2:44 pm

Unable to force auth on smtp, server transformed as spam relay after 2 days online

Post by Service »

[quote user="10330phoenix"]Yes, that will make it an open relay.[/QUOTE]
I can confirm that now ! Great no problem, everything works like expected, thanks for all !
Best regards.
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