I developed a new website for one of my clients, who already had a website www.domain.nl. In this domain there is a user account webXX_user with e-mail address firstname.lastname@example.org. First I developed the site in a temporary sub domain domain.obix.nl, having a user account webYY_user with e-mail address email@example.com. After finishing development, I first renamed the old site, i.e. www.domain.nl to domain_old.obix.nl and subsequently renamed the newly developed site, i.e. domain.obix.nl to www.domain.nl. The weird thing now is, that e-mail addressed to domain.nl winds up in the old mailbox. So instead of being dropped in the mailbox of user account webYY_user in the new domain, it's being delivered to the mailbox of user account webXX_user in the old domain. What could be the problem and is there a way to remedy it?