turn off open relay zimbra smtp

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plear_koeda
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turn off open relay zimbra smtp

Post by plear_koeda »

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
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Re: turn off open relay zimbra smtp

Post by phoenix »

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.
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Bill

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plear_koeda
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Re: turn off open relay zimbra smtp

Post by plear_koeda »

the output its
Release 8.6.0_GA_1153.RHEL7_64_20141215151110 RHEL7_64 FOSS edition.
phoenix
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Re: turn off open relay zimbra smtp

Post by phoenix »

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

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GDA
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Re: turn off open relay zimbra smtp

Post by GDA »

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
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Re: turn off open relay zimbra smtp

Post by phoenix »

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.
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Bill

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GDA
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Re: turn off open relay zimbra smtp

Post by GDA »

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
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Re: turn off open relay zimbra smtp

Post by phoenix »

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!!
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Bill

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GDA
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Re: turn off open relay zimbra smtp

Post by GDA »

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
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Re: turn off open relay zimbra smtp

Post by phoenix »

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.
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Bill

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