I've been getting various and sundry reports for the past few months that my outgoing email is not being delivered, randomly. If you wrote me and I didn't respond, drop me a line. I can receive emails just fine. I'll respond to you using another account that seems to be working.
So, in short, I haven't intentionally been ignoring anyone. Sorry for any inconvenience.
I think I've fixed the problem. Unfortunately, it looks like it's been going on for more than a few months. Maybe even more than a year! It wasn't malware, as I suspected, but an advanced settings tab that I needed to make some refinements to. Darn computers.
Sorry for all the weeping (Rachel ;). I really do return emails. Faithfully.