turn off open relay zimbra smtp

Discuss your pilot or production implementation with other Zimbra admins or our engineers.
plear_koeda
Posts: 2
Joined: Mon Sep 06, 2021 11:01 am

turn off open relay zimbra smtp

Postby plear_koeda » Mon Sep 06, 2021 11:04 am

Hi ,
i have big problem with my server
my zimbra server was spamming over 2000 mails (using remote smtp ) , so anyone can access my server without authentication
for example i have domain xyz.com then others can send with domain @abc.com
i test with smtp test can user my outgoing server without authentications.
how i can solve this open relay problems?.


phoenix
Ambassador
Ambassador
Posts: 26878
Joined: Fri Sep 12, 2014 9:56 pm
Location: Liverpool, England

Re: turn off open relay zimbra smtp

Postby phoenix » Mon Sep 06, 2021 2:32 pm

How about an internet first (it should provide the answers): https://www.ecosia.org/search?q=zimbra+open+relay

BTW, you should always post the ZCS version by giving the full output of the following command:

Code: Select all

zmcontrol -v
You should also give some description of what changes you've made to your ZCS server as it's not an open-relay by default.
Regards

Bill

Rspamd: A high performance spamassassin replacement

Per ardua ad astra
plear_koeda
Posts: 2
Joined: Mon Sep 06, 2021 11:01 am

Re: turn off open relay zimbra smtp

Postby plear_koeda » Mon Sep 06, 2021 3:09 pm

the output its
Release 8.6.0_GA_1153.RHEL7_64_20141215151110 RHEL7_64 FOSS edition.
phoenix
Ambassador
Ambassador
Posts: 26878
Joined: Fri Sep 12, 2014 9:56 pm
Location: Liverpool, England

Re: turn off open relay zimbra smtp

Postby phoenix » Tue Sep 07, 2021 6:12 am

You need to get on the most recent release ASAP, older versions have serious security vulnerabilities which may get hacked.
Regards

Bill

Rspamd: A high performance spamassassin replacement

Per ardua ad astra
GDA
Posts: 10
Joined: Thu Sep 09, 2021 10:59 am

Re: turn off open relay zimbra smtp

Postby GDA » Wed Sep 15, 2021 10:33 am

Hello. I have a version Release 8.8.15_GA_3869. And I also have problems sending spam, and the SMTP tests say my server is open relay. Please help me, how can you close this problem?
phoenix
Ambassador
Ambassador
Posts: 26878
Joined: Fri Sep 12, 2014 9:56 pm
Location: Liverpool, England

Re: turn off open relay zimbra smtp

Postby phoenix » Wed Sep 15, 2021 10:43 am

GDA wrote:Hello. I have a version Release 8.8.15_GA_3869. And I also have problems sending spam, and the SMTP tests say my server is open relay. Please help me, how can you close this problem?


Tell us what changes you made to the ZCS mtamynetworks settings? Changes to that can cause an open relay and ZCS by default is not an open relay, you can also check the wiki article on the subject of mtamynetworks and verify what your settings are.
Regards

Bill

Rspamd: A high performance spamassassin replacement

Per ardua ad astra
GDA
Posts: 10
Joined: Thu Sep 09, 2021 10:59 am

Re: turn off open relay zimbra smtp

Postby GDA » Wed Sep 15, 2021 11:28 am

phoenix wrote:
GDA wrote:Hello. I have a version Release 8.8.15_GA_3869. And I also have problems sending spam, and the SMTP tests say my server is open relay. Please help me, how can you close this problem?


Tell us what changes you made to the ZCS mtamynetworks settings? Changes to that can cause an open relay and ZCS by default is not an open relay, you can also check the wiki article on the subject of mtamynetworks and verify what your settings are.


mynetworks = 127.0.0.0/8 172.16.10.30/32 213.xxx.xx.xx/32
phoenix
Ambassador
Ambassador
Posts: 26878
Joined: Fri Sep 12, 2014 9:56 pm
Location: Liverpool, England

Re: turn off open relay zimbra smtp

Postby phoenix » Thu Sep 16, 2021 8:41 am

As has been mentioned many times in these forums and on the wiki article, the problem is the fact that as you're on a private LAN for your server then adding the public IP will make your server an open relay - remove it as per the wiki article!!
Regards

Bill

Rspamd: A high performance spamassassin replacement

Per ardua ad astra
GDA
Posts: 10
Joined: Thu Sep 09, 2021 10:59 am

Re: turn off open relay zimbra smtp

Postby GDA » Thu Sep 16, 2021 10:13 am

phoenix wrote:As has been mentioned many times in these forums and on the wiki article, the problem is the fact that as you're on a private LAN for your server then adding the public IP will make your server an open relay - remove it as per the wiki article!!

This is the only way to close an open relay. And if a lot of spam leaves zimbra, and there are no compromised user records, what should be done in this case?
phoenix
Ambassador
Ambassador
Posts: 26878
Joined: Fri Sep 12, 2014 9:56 pm
Location: Liverpool, England

Re: turn off open relay zimbra smtp

Postby phoenix » Thu Sep 16, 2021 10:40 am

Yes, you need to remove the public IP to stop it being an open relay. If you are still having spam sent through your server you should check all the machines on your LAN for any infections or bots - that should also include the ZCS server.
Regards

Bill

Rspamd: A high performance spamassassin replacement

Per ardua ad astra

Return to “Administrators”

Who is online

Users browsing this forum: Google [Bot] and 38 guests