Because this is an issue inherent primarily with bulk mail, we remove all identifying information *except* the unsub link, which *should* have a unique identifying token embedded within, from which the sender *should* be able to determine the complainant's email address. And, if there is no such link, we use that as an opportunity to educate them as to *why* they need to include such a link (mind you, in order to be accredited with us the sender has to have already demonstrated that they comply with including an unsub link, but because many of our accreditation customers are ESPs, their customers may sometimes not be modelling 100% of best practices).
Regardless of unsub link, or anything else, if we get a spam complaint against one of our customers, we hold their feet to the fire, and require them to explain exactly how the particular list was built, how the address was acquired, etc.. Failure to do so can (and usually does) result in termination of their accreditation - in the case of an ESP, they have to take corrective measures against their spamming customer or the ESP will lose their accreditation.
Anne
Anne P. Mitchell, Esq.
Author: Section 6 of the CAN-SPAM Act of 2003
CEO/President
Institute for Social Internet Public Policy
http://www.ISIPP.com
Member, Cal. Bar Cyberspace Law Committee
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