• Is the information provided for the outgoing email server hostname, username, and password correct?
• Is SMTP Authentication working correctly on the email server? This may be a question for your ISP.
• Is the port number in use correct? For SMTP Authentication to function correctly, the port should be 587 or 465, not 25.

• Static - not dynamic!
• An outbound mail server
• Configured with appropriate Reverse DNS
• Assigned to the individual or company performing the removal

• End-user single-IP exclusions from PBL Zone Listings expire after one year, and will be immediately reversed if spam is detected from them.
• ISPs with PBL Accounts may select shorter expiration periods for exclusions, and may add or remove lists of many such single-IP exclusions.

• Have at least one IPv4 /24 or IPv6 /48 allocation identifiable by IP-Whois, rWhois or rDNS;
• Network records for that allocation must contain and clearly identify their Primary Domain;
• Must have a working abuse@yourprimarydomain e-mail for that Primary Domain;
• Email addresses used to fill in the "Your Work Email" and "Role Contact Email Address" fields in the PBL Account application should also use the Primary Domain of the PBL Account application, or a domain we can easily identify as being related to the ISP making the request.

Please ensure that the difference between "Master Ranges" and "PBL Zone Listings" is fully understood before entering IP ranges in a PBL account.

1. Read the ISP Account description;


2. Fill out the ISP Account application form;


3. The Primary Domain should be chosen carefully.
• Spamhaus must be able to verify that the Primary Domain matches domains found in the IP-Whois, rWhois or rDNS records for the requested Master Range.


4. An applicant must be able to read email sent to the abuse@yourprimarydomain account;
• All communication regarding the new account will be sent to this email address
• The confirmation message will come from "spamhaus_pbl_verify@spamhaus.org"


5. Please follow the instructions in the confirmation email.

1. Log in to the new PBL Account.
   • Click the "Add Master Range" link in the list on the left-hand side, and follow the instructions on that page to claim a Master Range.
   • Any or all ranges which are allocated to you may be claimed, and more of your allocated IP ranges may be added at any time.
   • We will look up each claimed range, confirm ownership, and add it as a Master Range to your account.
   • It may take us a day or two to verify ownership and approve new ranges.
   • Master Ranges will be marked "approved" as soon as we verify them.
   
   
2. Once the Master Range(s) are approved, PBL Zone Listings may be entered.
• They will be kept in "Status: Pending" and not entered in the PBL until the related Master Range for your account is approved.


3. Be sure that PBL Zone Listings do not include IPs that are intended for outbound mail servers.
• Spamhaus encourages ISPs to add any and all IP ranges that are not intended to send outbound mail as PBL Zone Listings.
• PBL Zone Listings will only be added to the PBL after Spamhaus has verified that the IPs belong to your Master Ranges.
• Within approved Master Ranges, PBL Zone Listing additions or removals will take place immediately.


4. Each PBL Zone Listing must have a PBL Policy that applies to that Listing.
   • Once logged into your PBL Account, there is a link to "Policy Records" on the left-hand side of the page. This link allows:
     • The text of one or more policies to be entered;
     • The determination in regard to whether or not end-users are allowed to remove individual IPs;
     • The specification of the length of time before such removals expire.
   • Any Policy can be applied to any PBL Listing within your range and the Policy can be changed at any time, but only one policy at a time per listing.
   • Any existing Spamhaus listings within a Master Range may be claimed as your own, and a PBL Policy of your choice assigned.
   • They may be left as-is, under the default Spamhaus policy which allows end-user removals, or they may be removed if they are to host outbound email servers.
   
   
5. That's it! Changes can be made to your PBL Account at any time as changes are made to your network. Thank you for helping make the Internet a better, more spam-free place!

• The confirmation code will be sent to that abuse@yourprimarydomain email address.
• Ensure that email address can recieve email, and then request a new confirmation code.

As soon as the confirmation is completed, our systems will send you a password for your PBL Account. If necessary, a new password can be requested.

• The password will be sent to abuse@yourprimarydomain.
• Ensure that email address can receive email, and then request a new password.

• "PBL Zone Listing" refers to subsets of Master Ranges which are intended for inclusion in the PBL;
• "PBL Zone Listings" are IP addresses that are listed in the DNSBL zone pbl.spamhaus.org;
  • Email sent from outbound email servers running on IP addresses listed in the DNSBL pbl.spamhaus.org (PBL Zone Listings) may be rejected by any server using PBL or Zen data.
• Authorized ISPs may add or remove any IP range(s) from the subset PBL Zones Listings that are within their Master Ranges.

• A "Master Range" is typically the same as the allocation the ISP is granted by their Regional Internet Registry;
• "Master Ranges" are the IP ranges assigned to a PBL account by Spamhaus, and define the IP ranges in which that account is authorized to create PBL Zone Listing records;
  • Spamhaus assigns Master Ranges based on information gathered from Whois, rWhois or rDNS after the application for that range is received.
• None, some, or all IPs in a Master Range may be listed in PBL Zone Listings by the ISP at their discretion, as long as the changes remain within the guidelines expressed previously.

• Changes to Master Ranges can only be requested by entities who are authorized.
• Once an ISP requests and is granted authority over their Master Range(s), and Spamhaus validates that request, ISP can change "PBL Zones Listings" within their "Master Range(s)".
• Such changes will become active after the next zone build, within 15 minutes of the change.

• Tick the checkbox next to the desired the CIDR range(s);
• Click the "Remove selected listings" button.
• Removed PBL Zone Listings will disappear from the PBL in just a few minutes

• First, remove the old PBL Zone listing
• Then use the "Add PBL Zone Listing" link on the left-hand side of your PBL account to add the desired CIDR ranges to the PBL Zone Listing

192.0.2.0/24
!192.0.2.16/31
!192.0.2.248/29

• List the entire CIDR range and then quickly delete that range.
• Be sure to tick the checkbox labeled "Overwrite conflicting listings".

• Tick the box next to the relevant CIDR range, then click "Remove selected listings".
• PBL Zone Listing(s) made by Spamhaus within your Master Ranges can be claimed, and your own PBL Policy applied, by following the links on the left-hand side of your PBL Account.

• Zen contains the SBL, SBLCSS, XBL and PBL blocklists.
• Connections from IP addresses listed in Zen can safely be rejected during the SMTP transaction.
• PBL should only be used for SMTP (email).
• Please see the DNSBL Usage FAQ for general information on using Spamhaus DNSBL zones.

• ISPs should ensure that:
• Their smarthost email servers are configured to use SMTP Auth;
• Specific instructions are published for their users regarding the configuration of SMTP Auth in their local email program;
• Their users are otherwise allowed access to the servers (for example: whitelisting of local dynamic ranges).

• It is normal for legitimate emails to originate from an IP listed in PBL;
• That IP will usually appear in the message headers, and should not be used as a basis for blocking;
• In order to be effective, PBL must be used exclusively for checks at the SMTP connection level.

PBL should not be used for URL-based blocking.

• Using it to block URLs will lead to potentially large numbers of false positives
• Legitimate webservers are often hosted with dynamic DNS services such as dyndns.org, noip.com, freedns.afraid.org, etc.
• ISPs and other networks are encouraged to list any IP ranges which should not send mail, and that should include web servers.
• SBL or XBL (or sbl-xbl.spamhaus.org) should be used for URL blocking as described in our Effective Spam Filtering section.

• Legitimate users will have PBL-listed IPs showing in the first (lowest) "Received header" where their personal computer hands off the email to the ISP.
• Email should NOT be blocked for this

NS lookup of an inverse address which is not listed in PBL will return NXDOMAIN, like any other Spamhaus zone:

$ nslookup 2.0.0.127.pbl.spamhaus.org
...
Name:   2.0.0.127.pbl.spamhaus.org
Address: 127.0.0.10

$ nslookup 1.0.0.127.pbl.spamhaus.org
...
** server can't find 1.0.0.127.pbl.spamhaus.org: NXDOMAIN

• Like other Spamhaus DNS zones, it has is no 'A' record..
• For information about the technicalities of deploying and using PBL (and other Spamhaus DNSBLs), there is an extensive FAQ.

• Using PBL in this way will create a large number of false positives as it was not designed for this use.
• PBL is only designed to be used on incoming email.
• If the same server is being used for incoming and outgoing email, then the administrator must ensure that authenticated clients are exempted from PBL checks.
• A user may connect from a dynamic IP address that is in PBL and should remain in PBL;
• For users outside of locally whitelisted ranges, use Authenticated SMTP;
• Do NOT use PBL exemptions for this situation: this is not a problem that the use of PBL exemptions was designed to solve.

NOTE: This also applies to using the PBL to deny access to web-forums, journals or blogs.

• A PBL listing is NOT a result of any actions undertaken by the end users.
• The Spamhaus PBL is a list of IP space that should not be sending email direct to MX.
• Often these are IP ranges assigned by ISPs to broadband or dial-up customers, but the PBL does include other types of IP space.
• Any IP space that should not be sending email directly to the Internet should be listed in PBL.
• The majority of legitimate connections to webservers come from IPs listed in PBL, and should not be blocked because of their inclusion in the PBL.

• SpamAssassin-DQS
• Rspamd-DQS