Recently I had to perform an email migration moving domain1.com to domain2.com.  This was an easy task, but made more interesting due to the fact that we wanted to warn the public that we were changing domain names.  The basic setup of the users was each account had a primary address as domain1.com and at least one alias for domain2.com.  Our plan was to flip this relationship so all users would be logging in with the correct address, but still be able to receive mail at the old domain until we decided to remove it.  We use Zimbra for a mail server, so there is a rich command line ability to take advantage of. Read the rest of this entry »