Migrate email accounts and forwardings

[landauf]

The email accounts (including all stored emails) and all email forwardings should be migrated to the new server.

The migration should happen in an "atomic" step, i.e. it shouln't be possible that mails are still received on the old server AFTER the accounts were migrated because that would result in a loss of data.

Loss of data should be avoided in general. It is however acceptable if the email accounts are unavailable for some hours.

[lferran]

• I assume that the migration of stored emails only applies for users that we migrated (Tickets 433 and 454) that had a <user>@orxonox.net mailbox in the old server.

• Regarding email forwardings: they can be configured from the LDAP admin panel. According to landauf: most users are <username>@ee.ethz.ch anyway, and for some older users, he know the private addresses

• The procedure would be to:
  1. Inform everyone about the period when the migration is being done
  2. Re-configure new server (.info → .net)
  3. Stop postfix service in old server. Put dovecot to read-only (or stop, alternately)
  4. Migrate stored emails
  5. Change the DNS entry for mail.orxonox.net → new server's IP
  6. Test that everything is allright
  7. When so: inform all users

[lferran]

@landauf: do you know how are email redirects configured in the old server? We should fetch them, and re-configure them in LDAP.

[lferran]

The above issue has been fixed in ticket:480