Yahoogroups.com does not support email addresses "info@domain"
Problem: Yahoogroups.com, the free mailing list service by Yahoo, does not permit email addresses where the local part of the name is info, e.g. firstname.lastname@example.org. If you subscribed to a list using such a name, you may have been unsubcribed by the mail system. If you try to subscribe, you will be told that email@example.com is not an email address (which is nonsense, of course).