What is https://www.pages04.net/ ?
WMF has given them a copy of (a subset of..?) the donor email list, as this link has Peter's email address on the page:
https://www.pages04.net/wikimedia/WMFUnsubscribe/Unsubscribe?spMailingID=520...
If you dont want to try that link, the following will give you a general idea of the form donors are being directed to:
https://www.pages04.net/wikimedia/WMFUnsubscribe/
-- John Vandenberg