It seems that some people have just given up trying to fix/workaround the issue, e.g. this TM auction:
http://www.trademe.co.nz/a.asp?id=156671336
 
Quote:
"xtra.co.nz user PLEASE DO NOT BID, Seller is tired of email being trapped by xtra's spam filer. If you insist to bid, use only hotmail or gmail account to write to seller. Thanks."
 


 
2008/5/28 Skip Parker <skip@ignition.net.nz>:
Has anyone had any experience on using a certified email solution like
Goodmail's CertifiedEmail in relation to combating Xtra/Yahoos over zealous
spam filters?

Like others were basically numb from bashing our heads against the Yahoo
Wall.

Skip Parker




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