lost email upon upgrade to Mavericks - missing spam folder

I’m running a Mac Pro (4,1) 2.66 Quad late 2009. When I upgraded the OS from 10.6.8 to Mavericks 10.9.3 there was a major reshuffling of Apple Mail data and I stopped getting all email. I tried sending some mail to myself and saw it pop up briefly, for less than a second, then disappear. I checked rules under Apple Mail preferences and found the SpamSieve rule was the culprit. Found this – “if <any> of the following conditions are met: <every message> Perform the following actions: <Move Message> to mailbox <Spam> folder.” But gosh darn it, there was no folder titled “spam.” Per my trials and experience of continuing to email myself, the mail seems to be working after unchecking all the rules in preferences. Maybe not as well as before though because I am seeing notifications of new mail pop up on my screen, but I don’t see them in Mail. Anyway, most importantly, any ideas where my email disappeared to or where the spam folder might be? Also any suggestions on re-starting SpamSieve so it will work right? I guess just start over in that regard with training the re-training the SS software. Thanks for considering my issues. I appreciate any help you can provide.

Found it! --Per your answer to another question — Normally it doesn’t go anywhere. If you can’t see the mailbox, please see What can I do if my Spam mailbox in Apple Mail disappeared?.

Here’s the link. If Mail is hiding a section of mailboxes, you can show the by clicking the Show button (which is only visible when you move the mouse over the section header). To see where your Spam mailbox is, click on its name in the SpamSieve rule. This will show its location in the mailbox hierarchy.

Re-educating SpamSieve

Thanks Michael. Do you have any advice regarding re-education the SpamSieve program regarding what is good and what is spam? Seems like itis missing a bunch of things on both sides of that equation.

Please see the Why is SpamSieve not catching my spam? page.