Migrate our mail server (ldap/postfix/cyrus) to google apps

Hello, We are a company with about 25 user accounts and about 36 GB of mail data (including cyrus squatter indexes). Our mail is currently served by a Centos4 mail server with postfix as MTA and cyrus as backend. Our users access their mail via secured IMAP (TLS) or via squirrelmail (https). Our users and their passwords are stored in an openldap server. Postfix, cyrus imap and openldap used are the from latest version from Centos 4. We use a combination of spamassassin, clamav and sagator to reject spam and viruses. We also have a mailman service for about 30 mailing-lists. We have a 4Mb/s SDLS connexion to Internet. Our server is reaching its limits (both storagewise and CPUwise) and instead of upgrading it, we would like to move to google apps (Premier Edition). We are looking for someone to manage this move. Here are some of our most important requirements: Probably easy: a) our users should keep all their existing mails b) our users should be able to access their mails through IMAP (SSL or TLS) with their thunderbird clients as well as with the google web interface c) some users have special aliases (like johnny _at_ [login to view URL] -> john _at_ [login to view URL]) Harder ? d) our users should be able to use both firstname _at_ [login to view URL] and lastname _at_ [login to view URL] to get their mails (in our current setup, lastname is the account name, and we create the firstname alias based on ldap data) e) The login name should be the ldap account name (we use the lastname) f) our users should continue to get mail for different domains (john _at_ [login to view URL] and john _at_ [login to view URL] should both work) g) We might want to introduce a third domain (john _at_ [login to view URL] and john _at_ [login to view URL] and john _at_ [login to view URL] should all work) h) the transition should take place during a weekend (Paris time) and no mails should be lost. Maybe, we can do an incremental update via IMAP (for many days if needed) so that most of the old mails would be there by the migration date and the weekend migration would only be copying the 'new' mails to google apps. Even harder ? i) I would like the passwords for the mail accounts to be fetched from our ldap server live j) Creation of a user in ldap should also create the associated mailbox and configuration on google apps k) We want to be able to continue to use our mailing-lists (either self-hosted or via google apps) l) a special alias 'everybody _at_ [login to view URL]' should send mail to everybody (with a valid ldap account) m) some special aliases should be created/updated based on ldap group membership. Eg as long as a user is in the ldap group 'accounting' they should receive mails sent to 'accounting _at_ [login to view URL]' n) Ideally, hyphen-addressing should continue to work (ie one user 'john _at_ [login to view URL]' should be able to give any address of the form 'john-anything _at_ [login to view URL]' and get their mail automatically in their mailbox Since we know that google only supports plus-adressing [login to view URL];answer=12096 we can think of a phase-out transition of about 6 month where minus-adresses are rewriten into plus-addresses on a front server. This server should give us a list of the re-written addresses regularely so that our users can update them. A tgz file with our current configuration files is available upon request. What I expect: 1) understanding of our situation and critical analysis of our requirements (maybe I forgot something important !). Feaseability analysis of our requirements a) to n). If some requirements are not (or do not seem) possible, discussion with me to find the best workaround 2) detailed technical documentation on HOW to do the move. Should we have a problem, the 'rollback' procedure should be clear too. 3) Help with the actual move Each step should be validated by me prior to taking the next step. Best regards, Antoine NOTE1: g) looks easy: we could start with the setup of [login to view URL] on google apps, get things working, and only once everything is OK change the MXs for our other domains and switch the users to use google apps. NOTE2: c) d) f) g) and n) mean that a user "john doze" with special alias johnny should be able to read their mails sent the following addresses from the same account: john _at_ [login to view URL] doze _at_ [login to view URL] johnny _at_ [login to view URL] john _at_ [login to view URL] doze _at_ [login to view URL] johnny _at_ [login to view URL] john _at_ [login to view URL] doze _at_ [login to view URL] johnny _at_ [login to view URL] john-anything _at_ [login to view URL] doze-anything _at_ [login to view URL] john-anything _at_ [login to view URL] doze-anything _at_ [login to view URL] john-anything _at_ [login to view URL] doze-anything _at_ [login to view URL] doze+anything _at_ [login to view URL] doze+anything _at_ [login to view URL] doze+anything _at_ [login to view URL]