I've coined the word "Scrolliosis" to describe an affliction that has been thriving in the ecosystem of my e-mail inbox for years.
I get a lot of e-mail. Some of it makes up "hot items", which I'm obliged to tackle right away. These are usually revenue generating activities such as client communications. There are also "warm items", which are non-spam messages that come directly to me or from high-priority mailing lists (only the 4Suite ML in my case). The volume of warm mail alone is overwhelming, and it falls into one of two categories:
It comes at a moment when the time I happen to have available exceeds the time that it appears to require, at first glance.
It comes at a moment when the time I happen to have available falls short of the time that it appears to require.
Eventually I get a free moment and start on all the stuff that falls into category 2, starting from the most recent and working backwards. Unfortunately, at present I have 366 warm items in my inbox (never mind the 150 or so "cool" items in my pending folder which are basically a matter of get-to-it-in-the-very-unlikely-chance-that-I-ever-can).
This means that once a warm item has scrolled sufficiently far up in my inbox, the chances start to dwindle that I'll get to it in reasonable time. In that case that item has been afflicted by scrolliosis. Today I happen to have set myself a goal of cutting my inbox to 300 messages, so I'll see how much I can rescue from scrolliosis.
The real message is that if you've sent correspondence, and I've not always been prompt, please don't take offense. I'm harried, but probably not trying to be rude. I do also respond to polite reminders. I'm sure many of my colleagues have the same problem.