This article was originally published in Turkish on and migrated from our previous website. This English version translates the archived article. Service lists, product features and time estimates may be outdated and are not current guarantees; check current official information before acting.
The source describes organizations that monitor email traffic and list IP addresses associated with potentially harmful activity. If your outgoing mail IP is blocked because of problematic email traffic, it has been blocklisted.
Receiving mail servers using that RBL may reject your messages, disrupting email delivery for customers.
The original article offers a list of RBL addresses for an SMTP server’s DNS Blacklist settings. This table is retained as historical reference; it is not a recommendation to enable all listed services today.
| Blocklist RBL server address | Best-practice index (source label) |
| access.redhawk.org | 22 |
| accredit.habeas.com | 14 |
| bl.deadbeef.com | 20 |
| bl.spamcannibal.org | 36 |
| bl.spamcop.net | 2 |
| blackholes.uceb.org | 37 |
| blacklist.spambag.org | 30 |
| cbl.abuseat.org | 3 |
| cbl.ni.bg | 38 |
| cblless.anti-spam.org.cn | 35 |
| combined.njabl.org | 11 |
| combined.rbl.msrbl.net | 31 |
| dnsbl.ahbl.org | 18 |
| dnsbl.burnt-tech.com | 19 |
| dnsbl.delink.net | 21 |
| dnsbl.njabl.org | 10 |
| dnsbl.sorbs.net | 4 |
| dnsbl.tqmcube.com | 27 |
| dnsbl-1.uceprotect.net | 32 |
| dnsbl-2.uceprotect.net | 33 |
| dnsbl-3.uceprotect.net | 34 |
| dul.dnsbl.sorbs.net | 6 |
| http.dnsbl.sorbs.net | 7 |
| ko.tqmcube.com | 25 |
| list.dsbl.org | 15 |
| misc.dnsbl.sorbs.net | 9 |
| multihop.dsbl.org | 16 |
| no-more-funn.moensted.dk | 23 |
| prc.tqmcube.com | 26 |
| psbl.surriel.com | 29 |
| rbl.spamlab.com | 13 |
| sbl-xbl.spamhaus.org | 1 |
| smtp.dnsbl.sorbs.net | 8 |
| socks.dnsbl.sorbs.net | 5 |
| spam.tqmcube.com | 24 |
| ubl.unsubscore.com | 28 |
| unconfirmed.dsbl.org | 17 |
| zen.spamhaus.org | 12 |
The original article points to http://www.blacklistalert.org. Enter an IP address or domain to check whether the sending IP is listed.
The article identifies blocklisting as a common server-administration problem. It recommends preventing spam from the server and avoiding nulled or warez themes in installed applications.
Leaving the Barracuda blocklist
Source note: The original article claims that HostTurka’s different outgoing email architecture avoids this type of issue and says the guide is intended for people managing their own servers. This historical wording is retained for fidelity and must not be treated as a present-day unconditional deliverability guarantee.
Turkey (Türkçe)
Worldwide (English)