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MrChrister
Asked: 2010-01-08 23:45:21 +0800 CST

How to change web host and have minimal downtime for email

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In a question related to making a smooth transition to a new shared hosting provider, I want to move the email and web sites as smoothly as possible. I am a developer but have gotten into consulting my friend on what to do.

Company S currently has us using a Google AFYD account for our email. Therefore I can access my email via the web and Google's site. Am I correct in thinking even if the DNS mumbo jumbo that was setup to match mail.DOMAIN.com to the AFYD account goes away, I can still access the account (if it isnt' shut down by the admin)? CrystalTech will be hosting our new email and I have a web interface with them as well that I can get to via a unique URL.

But the customer is adament that her company cannot use webmail for more than a day, and even that day would be painful.

How can I move the email server to the new host with the least amount of downtime?

Clarification - Their office uses entourage, so all email is in their clients. - I have already setup the new hosting with similar accounts to the old - We have instructions on how to setup the email client for the new host - Web mail should be available as a backup in case it all goes to heck.

please see https://superuser.com/questions/93009/how-to-change-web-host-for-my-small-site-with-minimal-downtime for more questions about migrating the website

domain-name-system email shared-hosting

2 Answers

  1. Best Answer

    I gave the answer on your other question.

    Your best bet is to pre populate the DNS with all the relevant MX records on your new provider before moving nameservers.

    This will mean that you will have ZERO downtime as no matter what stage the changeover is at, a query to either the old or new DNS server will get resolved.

    ... even if you wanted to switch email providers, you can still get zero downtime by doing something similar - create all mailboxes on the new provider and then update DNS to point to the new place. Set up all clients to login to both old and new providers. You will still get emails on the old mailboxes until every cache expires, but after this, the new one will simply start getting all the emails... then simply deactivate/delete the old mailboxes when you know it is finished with.

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  2. I can't tell what you mean by reading the question. Are you changing mail servers or not? If you are, BEFORE CHANGING THE DNS set up the old servers to forward to the new (at a different name). For instance:

    1. Assign the new server the name "newserver.yourdomain.com".
    2. Set up forwarding on the old server, so all new mail is automatically forwarded to the old server (for the same mailbox name).
    3. THEN, update DNS to reassign the original name (e.g. mail.yourdomain.com) to the new server.

    By following this sequence you end up with all mail after step 1 in mailboxes on the new server.

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