A cross between a "collector" and an "accidental" would be me. Ok...maybe a little of category 4, since I do have emails all the way back to 1999, but those are all personal ones that ten years earlier would have been hand written letters.
As a board member of our local historical society, it's interesting to contemplate the potential loss of so many of the day-to-day exchanges that so often give very telling glimpses into life in times past. Methinks those "anxious" hoarders may prove to be rather useful down the line.
We take photographic records of everything so much for granted - but sometimes nobody documents the ordinary; what did your neighbourhood look like 30 years ago? I live in a spot that, in 1840-1860 or so, had upwards of 60 houses, small shops and businesses. All completely gone now (in the 1900s a large part of it reverted to farmland), and no photographic record exists of any kind - because it just predated photography becoming widespread and common. How fascinating it would be to be able to see what it looked like then...
And I'm not telling you how many emails I have.
(and yes, I do weed. And yes, I do actually occasionally require info found in old ones...)