Frequently asked questions

What is the ASN DROP? Why am I listed on the ASN DROP? How do I remove an ASN from ASN DROP?

What is the Botnet Controller List (BCL)? How often is the Botnet Controller List (BCL) updated? How to obtain access to Botnet Controller List (BCL)? Can the BCL block legitimate traffic?

What is CSS? Misconfigured SMTP servers Why is my IP address listed in CSS? Removing an IP listed in CSS

What is the Domain Blocklist (DBL)? Why is a domain listed in Domain Blocklist (DBL)? All about removing domains from the Domain Blocklist (DBL) What is the "abused-legit" component of the Domain Blocklist? Why is a hostname listed in the abused-legit component of the Domain Blocklist? How do I remove myself from the abused-legit component of the Domain Blocklist? Can you scan my site and check that it is secure? Do the "abused legit" or "abused redirector" listings include full URL/URI links?

What is the eXploits Blocklist (XBL)? Why was my IP listed in the Exploits Blocklist (XBL)? I delisted my IP, but it keeps getting listed again. Why? I get error messages that I'm blocked by XBL, but when I check my IP on your site it's not listed. Why?

What is a botnet command and controller (C&C)? What is a blocklist? What is an Internet Protocol (IP) address What is a domain name? What is an Initial Access Broker? What is a top-level domain (TLD)?

IP listed in CSS - General help Misconfigured SMTP servers WiFi and Home Networks Closing Port 25: General Advice Hacked Website or CMS - General Information CMS-Specific help How can packet sniffing help find the problem?

What is the purpose of the HBL What is the HBL? Why am I listed on the Hash Blocklist (HBL)? How do I remove myself from the Hash Blocklist (HBL)?

What is "confirmed opt-in" (COI)? What to do about older, stale email lists (which are not purchased) but that have not been well maintained? What happens to contact lists when two companies merge, or a company is acquired? What is the Spamhaus policy regarding E-pending (Email-appending)? Regarding listwashing, waterfalling, and verification services Recommended reading for any email marketing company Misconfigured SMTP servers What about purchased or rented lists?

What is considered marketing or bulk email? What is the right way to send marketing e-mail? How not to do what spammers do... Email authentication How can we improve deliverability? How should I handle unsubscribe requests? How should I handle spam complaints?

What is the PBL? Help! My IP address is on the PBL! Enabling SMTP Authentication Why is Port 25 for email transmission no longer widely supported? Should I remove my IP address from the Policy Blocklist (PBL)? Single IP removal for outbound email server administrators Why can my freemail address not be used to request removals? What if I want to run a mail server on IPs listed in the Policy Blocklist (PBL)?

What is the SBL? Listing Criteria for inclusion in the SBL Is my IP listed in SBL? How do I get an IP removed from the SBL? Can I remove my IP from the Spamhaus Blocklist (SBL) if I am end-user? Is there any fee for SBL removal? When will my IP be removed from the SBL? I am a system administrator. How can remove my IP(s) from the SBL ?

What is the Zero Reputation Domain Blocklist (ZRD)? Why is a domain listed in Zero Reputation Domain Blocklist (ZRD)? How do I remove myself from the Zero Reputation Domain Blocklist (ZRD)?