LongevityCheck

Proposed Goal of Longevity Check:

Differentiate envelope-from domains and/or sending server IP addresses which have existed and consistently sent email for a threshold amount of time, from those who have not.

Potential loopholes the design of this check needs to keep closed:

Spammer could register a throw-away domain. Domains less than X days old would not pass this check.

Spammer could register and "age" throw-away domains past the X days threshold time period like a fine cheese, then put them into use. True longevity status however could be reserved for domains with a history of consistent use within the worldwide email system - thus artificially aged throw-away domains would not be seen by this check as having longevity.

Spammer could prepare domains for one-time use, by consistently sending mail from the IP address and envelope-from domain for the longevity threshold time period. They could send this mail to accounts of their own, at ISPs they know are contributing historical data to the Outbound Index.

Spammer would not be able to obtain accounts at all ISPs or non-ISP corporations which contribute historical data to the Outbound Index. Possibly their attempts to falsely present consistent traffic could be detected for this reason. Ideally, and automated score would indicate probability of this type of scam.

Needs to be tested and tuned against legit sender situations such as newly registered domains, new ISPs etc. This check can be used in combination with other checks, which would clear legit senders who have a longevity score that is similar to spammer longevity scores - where the spammer would not pass the other checks.