However, it was that search of the "to" field (which happened every Self-Search as well as the "to:" field searches) that caused massive slow-downs and prevented more than 10 or so days worth of history in the Self-Search. I solved these problems by only accepting valid screen names in the "To:" field and storing these in a search-friendly way.
With that, I had the problem of still accepting the "fake" users such as bang_list, etc that people had adopted. I created the "Bump List Register" to essentially register a fake user for the purpose of addressing into the "To:" field.
Make sense?
I was right!