Migrating from third-party providers to Office 365 – IMAP4 #1

December 8, 2012 by Peter O'Dowd in IT Infrastructure, Technical Documentation


Part 1: POP3 Example


IMAP4 Mailbox Migration Specifics – Example 1

This email provider, Northwind Traders, supports the IMAP protocol. Using the IMAP protocol allows you to migrate all mailbox folders (not just the Inbox as with POP3). Also, the provider allows the customer to configure their own address space and subsequently have MX records configured in DNS with their domain registrar to direct incoming email to the provider’s mail server.

Capability Example 1 IMAP provider
Domain name suffix Customer-specific; for example, contoso.com or treyresearch.com
IMAP migration YES
Admin account with Full Access NO
Export org address book NO
Export Contacts YES
Export Calendar NO

Unfortunately, with this provider it is not possible to export the address book of email addresses and mailbox information, nor is there a single account that has full mailbox access to all mailboxes. Consequently, it is necessary to work around these as follows. First, it is necessary to verify the domain name to Microsoft. Let’s assume that the name of the provider is Northwind Traders, and our registered domain name is treyresearch.com. Further details may be found at Verify a domain at any domain name registrar.

Verify the treyresearch.com email domain to Office 365 and configure it as an accepted domain

To create users with your treyresearch.com email addresses, you must specify the name, verify that you own that name, and then add it is an accepted domain. To do this:

  1. Log in to Office 365 using the administrator account, and navigate to the Domains page as shown in the following screenshot.

  2. Click Add a domain.

  3. Type the name of the domain and then click Next. In this example, treyresearch.com uses Go Daddy’s DNS to host their namespace, so we specify Go Daddy in the Office 365 dialog box.

  4. In the drop-down list, select Go Daddy.

  5. Office 365 provides great instructions here to assist with registering the domain. It is worth printing out the instructions. Click Print to print the instructions provided on the Office 365 site. If you cannot print, it may be necessary to switch between the screens.
  6. Open the Go Daddy control panel.

  7. Click Domain Manager.

  8. Click the domain name and then, under DNS Manager, click Launch.

  9. In DNS Manager, click Add Record.

  10. The Office 365 Help screen dialog boxes will provide you with the record details you enter at this point. Keep the printout at hand, or jot down the values. Once you have the record value, in the Add DNS Record dialog box, click the down arrow for the Record type: box, and then choose TXT (Text).

  11. For TXT Name, type or paste the following: @
  12. For TXT Value, type or paste the following: MS=ms87257449
  13. For TTL, leave the value set to 1 Hour.
  14. Click OK.

    Note: While you are editing the DNS records, now is a good time to confirm that the time to live (TTL) of the MX record is no longer than 1 hour. If it is, reduce it to 1 hour, which will make the final transition a lot smoother.

  15. Save the Zone File.

  16. Click OK.

Complete verification of the domain name

  1. Wait at least 15 minutes for the changes to take effect across the Internet. Come back to the Office 365 portal, and then click done, verify now.

    If the following screen appears, wait and try again later. In my experience, these names typically take less than 1 hour to resolve.

    Once confirmed, the following screen is displayed.

  2. Click Finish.


Create the Office 365 Mailboxes

Unfortunately, in our example with the provider Northwind Traders, there is no way to export the mailbox email addresses into a .csv file, so this must be done manually. Create a .csv file in the format shown in the following illustration. Create a row for each user and mailbox to be created. Save the .csv file locally to your computer. For additional information on Importing Users into Office 365 using a .csv file, see Add Multiple Users with Bulk Import and Import New Exchange Online Users with a CSV file.

  1. In the Office 365 portal, under Management, click Users.
  2. Click New and then select Bulk Add.

  3. Enter the name and path of the local CSV file and click Next.

    The user accounts and mailboxes will be created. Once complete, a results screen similar to the following will be displayed. Review the results and then click Next.

  4. Configure the sign-in status and user location.

  5. Select the licenses to apply to users.

    Note: Licenses may be changed and reconfigured later. For more information on assigning licenses, see Assign a License to New Mailboxes in Office 365.

  6. The user account passwords can be sent to an email account for management purposes. To do so, enter the email address and then click Create.

    Once created, the user accounts and passwords are displayed on the following screen.

Populate Office 365 mailboxes with hosted user mailbox email items

Now we need to connect to the host Northwind Traders, collect all of the users’ email, and place it in their Office 365 mailboxes. To do this, we use the built-in Office 365 IMAP migration tools. The IMAP provider Northwind Traders does not provide an administrator account to log in to all of the mailboxes and access email. Therefore the only way to get import to work is to create a .csv file as shown in the following illustration, with the users’ logon names and passwords. You have a couple of options here, depending on the security of the customer you’re a working with. In an environment where everyone trusts each other and the risk of anyone reading other people’s mail is insignificant, you could get all users to change their passwords to be the same, which makes creating the spreadsheet much easier. However, it is more than likely that this is not desirable, in which case you will need to gather each user’s password individually.

Create a .csv file

I recommend initially creating a .csv file with only a few test user accounts in it. Hopefully your users’ passwords are stronger than those in my example below!

Some providers require ’email address’ in the username field, and some require just the short username. Trial and error may be required here.

  1. Log in to the Office 365 portal as administrator, and then in Outlook Web App, click Options and select See all Options.
  2. On the
    options screen, click Manage Myself and then select Manage My Organization.

  3. Click the E-Mail Migration tab, click New, and then click Next.

  4. Select IMAP.

  5. On the Provide connection settings for your server (Step 1 of 3) screen, enter the server name (e.g., imap.nwtraders.com – the Northwind Traders IMAP server) and then click Next.

    Note: Your e-mail provider will be able to provide you with this name; however, it is likely that you are already know it as the name you use to connect your IMAP clients.

  6. On the Specify what and how to migrate (Step 2 of 3) screen, browse to the .csv file and enter a batch name. The batch name is for identification purposes only; e.g., I entered the name users A-J. Use an intuitive name here so that it will be easy to recognize what it refers to at a later stage.

    Here you get an opportunity to exclude folders such as Junk Mail and Deleted Items; check with the email provider mailbox for actual folder names you want to exclude.

  7. Click Next.

  8. Click Close.

    The migration batch will show a status of Created. Click Start to begin the migration.

  9. Click Refresh for updates.

When the procedure is completed, an email message will be sent to the administrator mailbox on Office 365. Open the email and download the report. Look for any errors in the email; typically, an incorrect password for a user mailbox will create an error. Recommended practice Initially, create a .csv file with just a few ‘test’ mailboxes listed in it to confirm that the format of the .csv file is correct and that mailboxes migrate. This is also a good time to record how long a mailbox takes to migrate and calculate the GB/hour transfer rate. This figure should be used to calculate the time required for a complete migration. Once a mailbox has been migrated, Office 365 will continue to synchronize the mailbox every 24 hours. Therefore it is possible to perform a migration where users continue to use their Northwind-hosted mailboxes until you have migrated all of the mail.

Migrating User Contacts

The Northwind Traders hosting environment provides no way for exporting contacts. Therefore, if your users want to have their contacts available in Office 365, they will need to export them and then import them into Office 365 themselves. Here’s an example of exporting contacts with the hosting provider Go Daddy. For additional information on importing contacts, see Learn More About Importing Contacts.

Export contacts

  1. Instruct your users to go to the Go Daddy workspace. Click the Email tab, and then click Address Book.
  2. Select Contacts.

  3. Click Export.

  4. Click Export CSV and save the user’s personal contacts to a .CSV file in a safe location. This will be imported into Office 365 when the user can access their Office 365 mailbox.


Import contacts into Office 365

  • In Office 365, click Contacts, click Import, and then in the Import Contacts dialog box, click Browse and select the .csv file the user saved prior to migration.

    That’s it – mailboxes have now been created and populated with historic email. Users have imported their contacts.

Switch the destination for email delivery to Office 365

Now it is time to switch over so that mail will be delivered to Office 365. To do this requires changing the MX record for your organization in DNS on the Internet. (Remember, we ensured that its TTL was 1 hour in previous steps.) Go back to the printout of those instructions and enter the value of the MX record that was given to you by Office 365. For more information, see Verify your domain and change name servers at any DNS hosting provider and domain registrar. For guidance on repointing MX records to Office 365, see Change MX Record.

Continue to Part 3: IMAP4 Example 2