[Note: To query the IADB you must fill out a short information form available here. There is no charge to query the IADB, and there will never be any charge to query the IADB, but we do need this information.]
IADB Query Instructions
The ISIPP Accreditation Database is an in-addr prefix style DNS list which resides at iadb.isipp.com.
When queried, the IADB will return one or more A records for any site which is listed in the IADB. These are as follows:
127.0.0.1 Listed in IADB
127.0.1.255 Vouched listing
127.0.2.1 Participates in Email Deliverability Database (EDDB)
127.0.2.2 Is a member of the Email Processing Industry Alliance (EPIA)
127.0.0.3 Publishes SPF record
127.2.255.1 Publishes SPF record
127.2.255.2 Publishes Microsoft “Sender I.D.” record
127.2.255.101 Participates in Habeas program
127.2.255.102 Participates in Ironport’s Bonded Sender program
127.3.100.0 Has absolutely no mailing controls in place
127.3.100.1 Scrapes addresses, pure opt-out only
127.3.100.2 Accepts unverified sign-ups such as through web page
127.3.100.3 Accepts unverified sign-ups, gives chance to opt out
127.3.100.4 Adds only customer and inquirer email addresses to mailing list without opt-in, gives chance to opt out
127.3.100.5 Has opt-in mechanism available, used less than 50% of the time
127.3.100.6 Has opt-in mechanism available, used more than 50% of the time
127.3.100.7 All mailing list mail is opt-in
127.3.100.8 All mailing list mail is at least opt-in, and has confirmed (double) opt-in mechanism available, used less than 50% of the time
127.3.100.9 All mailing list mail is at least opt-in, and has confirmed (double) opt-in mechanism available, used more than 50% of the time
127.3.100.10 All mailing list mail is confirmed (double) opt-in
127.3.100.100 The only email which comes from this IP address is mailing list email, and that mailing list email is entirely confirmed (double) opt-in
[ISIPP accepts recommendations for other data response codes which would be useful in addition to those listed above. If you would like to suggest a data point return which would be useful to email receivers, please email your suggestion to iadb at isipp.com]
Note that a query to IADB can return more than one response for any given listing; each response reveals one particular unique data point. For example 127.0.0.1 means that the site is listed in IADB, and 127.0.255.255 means that the listing is a vouched listing. Thus for a site which is listed in IADB and which is a vouched listing, a query will return “127.0.0.1; 127.0.255.255”, providing the querying site with the very specific information that the site is listed in IADB, and that the listing is a vouched listing. A return of “127.0.0.1; 127.2.255.1” would indicate that the site is listed in IADB, and the site publishes an SPF record.
ISIPP also offers receivers the option of receiving one “aggregated data point response” rather than the individual data point returns described here. This is particiularly useful to large ISPs looking to make email delivery handling decisions. For more information about the aggregate return, see the section below on “IADB2”.
The level of granularity provided by IADB allows querying sites to make decisions based on precise information regarding a listing in the IADB.
A detailed explanation of the data response codes is available here.
In addition, although not required, IADB listees may choose to include “X-IADB-IP:” and
“X-IADB-IP-REVERSE:” headers in the email they send (followed by the sending IP address, and sending IP address reversed, respectively). This provides a notice to receiving systems that a) the IP address in the X-IADB header should match the sending IP address, and b) the sending IP address and additional information about the sender can be found in IADB.
The IADB2 contains the same database data as IADB, however its responses are presented as an aggregate data point return ‘score’, rather than individual data point returns. Where IADB will tell the user that a given listed site is, for example, a vouched listing, and will also tell the user that the site publishes an SPF record, the IADB2 will return one single response which provides a weighted aggregate IADB score.
IADB2 allows large receivers to do a lookup, get a single-record return, and say, for example, “do X with email from any IP which returns a .30 or greater at the end of the record” (such as “accept”), and “do Y with email from any IP which returns anything smaller than .20” (such as, say, do a DNSBL check), or whatever they want to do, based on whatever “score” they decide is appropriate. The IADB2 aggregated response codes can be found here.
IADB provides the same information but with a greater degree of granularity and specificity about each bit of data, which is more useful to some sites and spam filter programs.
ISIPP also offers the WADB, the Withdrawn Accreditation Database. This is a list of sites which were once listed in the IADB, but have violated our listing criteria to the point of being removed, and listed in the WADB.
It is free to query all of the IADB, IADB2, and WADB.
Note that a query can return more than one response for any given listing; each response is option-specific. For example 127.0.0.1 means that the site is listed in IADB, and 127.0.0.2 means that the listing is a vouched listing. Thus for a site which is listed in IADB and which is a vouched listing, a query will return “127.0.0.1; 127.0.0.2”, providing the querying site with the very specific information that the site is listed in IADB, and that the listing is a vouched listing.
This level of granularity allows querying sites to make decisions based on precise information regarding a listing in the IADB.