Whenever I receive a spam email that appears to come from a Yahoo! Mail account, I send it off to abuse@yahoo.com and spamcop.net. About 3/4 of the time, some representative from Yahoo! rejects the spam email as having incomplete email headers. When I forward the spam email to Yahoo! and spamcop.net, I include it as an attachment with full email headers.
Spamcop.net will happily accept forwarded spam if the spam has full email headers. It will, likewise, reject any forwarded emails without the complete email headers.
Yahoo! appears to process the forwarded spam prior to sending it off to a live human. I suspect that either this processing sometimes wrongly strips the email headers from the spam or that some of the Yahoo! support people are just rejecting the forwarded spam under the guise of "incomplete email headers".
If anyone has any ties to Yahoo!, please let them know about this issue as I've been getting no where with them.
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