My OVH dedicated server is blacklist by SpamHaus

[laurent]

Hello,

It seems several people encounter this issue.

Can you help ?

Thanks!
Laurent Michel

[girish]

Yes, this is quite common. You have to setup a mail relay if you care about mail deliverability - https://docs.cloudron.io/email/#relay-outbound-mails

[gerard]

Hello, are you sure that your the Cloudron blocklist check works well and that the IP address DB is up to date ?
I'm experiencing the same issue than @laurent with an OVH dedicated server. Cloudron tells me that my server's IP address is on the Spamhaus ZEN block list.

• I tested my IP address directly on check.spamhaus.org : IP address "has no issues" !
• Then I tested it with mxtools: Green checkmark for Spamhaus ZEN !
• Then, again using mail-tester.com : Not listed on any Spamhaus blocklist

(although, mail-tester does not seem to use the ZEN list but shows 4 other Spamhaus list names)

So why does Cloudron tells me that it's on the ZEN blocklist ? Very strange.

[girish]

@gerard sometimes the outbound used is an IPv6 and not IPv4. Do you have IPv6 enabled on your server?

(There is an internal task to fix this on Cloudron side. It should display what is causing the error IPv4 or the IPv6 resolution).

[gerard]

Yes, I do have IPv6 enabled. But Cloudron displays that the IPv4 is blocklisted:
"This server's IP 149.202.72.125 is on a blocklist"
"SpamHaus Zen"
When checking this IPv4 with the previoiusly described services, it doesn't show up as blocked.

[malvim]

Same issue here. Cloudron says it's blacklisted by Spamhaus, but Spamhaus itself says it's not.

[girish]

I think this is because recently SpamHaus added a policy to not allow requests from many IPv6 blocks. Can you please check this:

• SSH into server and edit /etc/unbound/unbound.conf.d/cloudron-network.conf . Change the line do-ip6: yes to do-ip6: no .
• systemctl restart unbound

Does this help the SpamHaus check?

[gerard]

@girish That's it! SpamHaus check is now green.

[girish]

@gerard thanks for testing. A fix for this is coming next release.

The issue is fairly recent. SpamHaus made some policy change when requests come from IPv6 addresses.