I've never gotten or sent an email like that.
However, I want to use some things that have
happened to a friend of mine as an example of
the reverse type of situation.  (Names withheld
to protect the innocent and guilty both).

My friend collects a particular character which
another collector collects.  This person has a
lot of connections and spending money along with
a large collection of nice cels of this character.
The type of person who when you see an auction of
a cel of this character, they will usually be the
high bidder or have at least bid on it.

That's all fine and dandy.  Some people are more
willing to put in the time and effort to have the
best cels and if they're willing to do so, more
power to them.  I harbor no resentment towards
them because of this.

However, this particular person does have my
resentment because of their treatment of my friend
on occasions.  For example, complaining to my
friend about my friend getting a cel that this
person happened to want...even after they had
outbid my friend four or five times just that
week.  Or, another example, asking my friend not
to bid on a cel that this person knew that they
both wanted.

Just as no one gives up the "right" to buy a cel
because of how many cels that they have, no one
has the right to every cel of a character that
they want, only leaving the scraps that they don't
consider worth their while to other collectors.
This person's attitude is what has built up my
personal resentment, not their collection.