I need to allow same email for multiple users. The default configuration doesn't allow it so I changed every membershipprovider's requiresUniqueEmai="true" to requiresUniqueEmail="false" (in CMS and Commerce Manager sites).
But that didn't help. Commerce Manager doesn't allow me to change user email to one that's already in use.
Are there more configs that require update, or is this impossible with Episerver Commerce?
Save it as profile information instead on the user using EPiServer.Profile...?
I wan't to keep all the email properties in-sync (membership email + profile email). Otherwise it gets too complex to handle.
This is defined by code, then unfortunately you can't update through Commerce Manager UI. We will consider your requirement as a feature request and it might be implemented in next release.