The Duplicate Mail module has a block to display system wide duplicate email
addresses in user accounts, and a view with a block display for use on
individual user account pages that displays only the accounts that have the same
email address as that account.


This module lists user account information, including email addresses.
Restrict access to this information by configuring the blocks to only display
for a siteadmin type of role. (Picking a role other than anonymous or
authenticated will make it so anonymous or simple authenticated users cannot
see the blocks.) Configure block role visibility in Administer >> Site
Building >> Blocks and configure the Duplicate Mail blocks under Role specific
visibility settings.

Also, change the region from Disabled to some other region. Right sidebar
works well for the system wide block. And content or content top works well
for the individual block generated by views.


If the blocks do not display, check the following:

- Make sure you save the block settings page after moving the blocks to a new

Why have this module

Q: It's impossible to get accounts with duplicate emails; why have this module?

A: There are a few modules that bypass that safeguard and allow duplicate
emails. And, during an import of users using the migrate module, accounts
can be created using emails already in use by other accounts.

This module is useful for listing only the accounts with duplicate emails
so that the users can be contacted to correct the situation, the accounts can
be merged, or just for information purposes to find out how many duplicates
there are.

Project Information