Spotlight SOMETIMES searches mail, but mail.app shows no results

Question

Hi folks,
  I've been anxiously waiting for the Mavericks release, hoping it would, once-and-for-all, fix this aggravating issue I've had with spotlight mail searches.
I recently carried out a full wipe-and-reinstall on my iMac, by creating a bootable clone of my main desktop, then booting from that drive and using disk utility to erase my main hard drive, and selecting that drive in the Mavericks installer.  This means that I had a 100% pristine installation of Mavericks - no old preferences, no old settings, no weird filesystem permissions issues, and yet this problem STILL persists.
I have three different Gmail email accounts, all connected via IMAP, and all saving the emails locally for offline viewing (although I don't believe this is an option anymore in Mavericks).  When I first added these accounts to Mail.app, I was unable to search them either in Spotlight or in Mail.app.
I have since undergone multiple attempts to fix it, and occasionally during the process Spotlight has worked(although it shows multiple historical versions of sent mails due to auto-save), but searching from within Mail.app remained broken no matter what I did.
These are the things I've tried:
running 'mdimport -r /Library/Spotlight/Mail.mdimporter'
adding and removing ~/Library/Mail to the spotlight 'do not index these files' privacy setting
adding and removing the entire hard drive to the 'do not index' list
using 'mdutil -E' to erase and rebuild the index
manually removing the Envelope Index files from ~/Library/Mail/V2/MailData, then re-launching mail to force it to rebuild the index
using the menus within mail to rebuild the mailboxes
This has been broken for several versions of Mac OS, and it's obscene that there hasn't been any progress on the issue.  Please tell me that somebody has some new ideas that I haven't tried yet - I've been struggling with this headache literally for YEARS, and it has really soured me on an otherwise excellent Apple experience.

Answer 1

I finally figured it out!
The trick was that I had some old versions of Mail.app in an archived folder, and these versions were screwing up spotlight, even though they haven't been run in years.  Removing the old versions, then updating the spotlight index and rebuilding the Envelope Index files seems to have fixed my search.
For others who, like me, have spent YEARS of constantly re-indexing things to fix it - there is an odd quirk in the way OS X associates files, where it seeks out Applications anywhere on your computer (including external hard drives), and the presence of those Applications can mess things up even if you aren't running them.  This seems to be rarely discussed in proposed solutions, but it was absolutely the fix for me.