The mystery: why some people trying to reach me got nothing but bounced e-mails, with the cringing apology from qmail that my account was full. Since I check my two faculty accounts quite often, I knew that was wrong ...
The answer: I have a third faculty account I never knew about. It was created sometime between 2001 and 2003 (they're not sure), that I've never read. It would be full from the many faculty-wide announcements received. With that figured out the people trying to e-mail me have already requested some of my time, and the account I didn't know about is scheduled for deletion.
Now of course this makes me regretful. I never used the account, sure, and the evidence suggests it'd be completely redundant to the other two accounts, and it doesn't come with a Unix terminal anywhere, so I haven't got a shred of use for it. I feel bad for losing it, and am trying to resist sending out a request that the account be spared, just in case I find some use for it sometime. Understand this feeling and you will understand something important about me, namely, that I'm a packrat and a nut.
Trivia: A topological space is called indiscrete if its only open sets are the null set and the entire set. Source: Functional Analysis: A Short Course, Edward W Packel. (The book includes a lovely mathematics joke; the author dedicated it ``to Lisa and Laura, my favorite little lp's,'' which makes sense if you know functional analysis.)
Currently Reading: The Struggle For Mastery In Europe, 1848-1918, A.J.P. Taylor.