Nothing's Perfect — Funny SPAM Detection

I've been itching to share this experience with everyone for a while now, but never got to actually write it. You know, I'm using gmail and I am receiving hundreds of emails (from mailing lists, bugzillas, real people etc.) each day (and for that reason I have a lot of filters to keep them sorted). And a tiny amount of these are SPAM. Sometimes google fails to detect obviously SPAM as such and I can understand that, however it is almost ironic how some perfectly sane and legitimate mails end up in SPAM folder. Ever since I noticed a mail from my thesis' advisor in SPAM folder I check every mail there. And among those that almost 100% end up there while they shouldn't are mails to webkit-dev mailing list from people with @google.com mail address. Funny, isn't it?