Comment 1 for bug 921994

Hi Patrick,

Unfortunately uniqueness of email addresses is not enforced at the db level yet. We may look at fixing that in future, but first I think we'd need to do a bit of work around how to upgrade old databases. In the meantime you should just avoid relying on uniqueness in your custom code.

If you find any core code relying on uniqueness of emails (you mentioned search friends, and see groups members), let us know in another bug report, and we'll fix it for 1.5.

See also https://bugs.launchpad.net/mahara/+bug/903494, https://bugs.launchpad.net/mahara/+bug/907903