When reading an HTML mail, it's hard to impossible to select the text you want for copy.  The selection happens, but it isn't necessarily where the mouse is.

It seems to select between mouse positions and single clicks.  Dragging the mouse alters the selection, but you can't choose the start point.

(It's a bit hard to explain exactly)

With the following:

apple
pear
banana

clicking on the 'e' in pear to select 'ear',  results in 'apple pe' to be selected.  Dragging to the right causes 'apple pear' to be selected.  It's not possible to NOT select 'apple'.

If you then let go completely, and click on the first 'n' in 'banana', 'ear ban' is selected, instead of just the 'n'.  ie. the start position has moved, but it hasn't moved to the new selection -- it's still stuck where the old selection was.