Migrating Local Mail Server to Google Apps

By | 19th Dec 2008 | 3 min read
We had a query from one of our customers to help them migrate their local mail server to Google Apps. They wanted to do this because they did not have the sufficient in-house capability nor have the funds to get paid external capability to support an internal mail server. One hurdle that they were facing was that they had around 40GB of mail left on the local mail server that they wanted to migrate to the new mail accounts they created on Google Apps.

One of the problems was that the local IMAP server kept on crashing whenever they tried the bulk import and then there were frequent authentication errors. We took up the project and completed the migration process within a week. The migration took that long because the complete 40GB(not quite because Google rejects huge attachments) had to be uploaded to Google over an unfavorably biased upstream channel.

The local mail server was dovecot and it was a pretty old version of dovecot too - pre 1.0. The IMAP server used to crash erratically during the bulk migration process but we worked around this by running a small script to restart the IMAP server if it went down after checking every minute. One good thing about the migration process with Google was that the bot was very patient and would retry on accounts that fail. So this 1 min interval ensured that the mail in the accounts from which import was happening at the time of crash always reached the Google server once the IMAP came back on.

Another problem was that there were quite a lot of authentication failures. It seemed that the mailserver was restored from a backup after some recent crash and this messed up the users and their uids leaving lot of mboxes orphans without valid users associated. Since the mboxes were named username we simply ran a script to move ownership back to the user with the same name. To add to the mess the local server was already compromised and was running a full scale spam relay service. We did not fix this issue as the server was going to be put to sleep after the migration. We worked around this issue by stopping all the unnecessary processes on the server other than the IMAP server.

Once the initial hiccups were sorted out the migration went smoothly and Google neatly imported the complete set of accounts and their mails from the local server. Google recognized the IMAP folders and labeled the emails accordingly while being imported into Google Apps. Other than the small concern that Google is going to have complete access to all your organizations mails there are no other reason that I could think off that should prevent small educational institutions in moving to Google Apps.

Google Apps offers free services for educational institutions. For commercial establishments a lite edition is free for use but the full and heavier version requires you to pay Google subscription charges. If you are a small user it might be better for you to avail the Free Services from Google and as you grow you can decide between the Free vs Paid services from Google or alternatively start looking at getting support externally initially and the finally hiring internal capability to manage your local servers.

Our Server Support Services and Migration Services

We however are happy to offer to any interested customers our services in remote administration of existing servers, i.e. if you are planning to get external help or if you are finding that paying for internal capability for the same is not entirely worth the money. For those who are looking to migrate to Google Apps, you can avail our services to have a hassle-free migration experience.