Removing Duplicate E-mail Addresses

Hello All!

As pretty much all e-mail processes de-duplicate by default (we use Wordfly, just in case anyone cares), this has always been a rather "low priority" thing for me, but in a recent data examination, I found that we have north of 10K accounts with 2 or more identical e-mail addresses (including one account that somehow gathered 19 identical records), so I figure it is about time to do something about it.

Firstly, does anyone have a good script for this?  Secondly, assuming I will have to do it myself (and happy to do so), does anyone know all the places e-mail addresses are saved that I need to consider?  The problem of course being just because Patron A has 3 identical e-mail addresses does not mean that they can all be summarily deleted.  Identical address 1 might be the "primary" on account while #2 might be the one tied to the TNEW login with #3 being tied to an old order.  Are those the only locations to which an e-mail address can be tied, or am I forgetting a few?

Note, for these purposes, at least at the moment, I am referring specifically to the situation of account A having 2 or more identical e-mail addresses; ignoring any such account B or C that has its own email address identical to those on account A.  We may pursue that direction in the future, but for now, this is a good starting point.

Thanks for any thoughts!

John