[6.0] Editing user's email changes several/all users' emails

Administrators of OpenERP 6.0 series sometimes face a strange behavior: changing one user's email seems to affect many users, possibly all of them. How can this happen?

This is typically caused by the "Address" (address_id) field of the users being the same.
In the 6.0 series, the "user_email" field is a related field that is directly linked to the email that is set on the address of the user. When you change it, it actually changes the email on the user's address. For this reason, all users should have different, personal address entries.

A common mistake is to try to assign the same address to all users, like a generic "Company address" or similar.
Normally when you create new users or duplicate them, the Address field is either emptied or linked to a fresh, new personal address, which will hold the user's email. If you ever re-assign a different address to the users, be careful to give them all separate addresses, or no address at all. If you don't set an address at all, a new one will be created on-the-fly if you assign an email - which is perfectly fine.

You can easily imagine the consequence if you share the same address with multiple users: they effectively also share the same email!

Note: if you install base_contact, the "email" field of the address becomes hidden, so it is less obvious to notice this, but the behavior will be the same. You should always make sure to keep separate addresses for the users, even with base_contact installed.

In the 6.1 series the Address of the user will be removed (it is apparently confusing for many users), and the "user email" field will become a normal text field, not a "related field" anymore - hopefully more intuitive.