We have a strange problem on the server running on odoo8.. We have a db user ABC@testing.com and a catchall domain as testing.com. Now I create a SO for a customer ABC@xyz.com. The customer receives the order by email..He clicks on the link from the email, odoo ask for the signup he signup, now a user is created for him. The strange thing is an alias is also created which is same as ABC(the system user).
The issue is raised because the mail.catchall.domain parameter is set to testing.com so there was a portal user with email login ABC@xyz.com and a messaging alias as ABC@testing.com same as ABC who is a real user of the system.
The question is how to avoid this in the future?
I suppose it is expense of using catchall tecnology and email aliases. You may creat an issue on github.com/odoo . Or write a module yourself to check new alias for the uniqueness.