3. Prepare your source account

Applies to Exchange 2003 or earlier, webmail providers, such as Yahoo!, and other IMAP servers.

You need to

• Choose a role account—When migrating from an IMAP webmail server, the Google Admin console prompts you to enter the username and password of the role account. This is an account on your source mail server. The data migration service uses it to test connectivity to your mail server. See Role account.  
• Google IP address ranges—Ensure your server connects to Google IP address ranges.

If required, see the additional setup steps for migrations from HCL Domino or Gmail.

These instructions apply to an existing Google Workspace account. If you selected the Gmail migration option, see Personal Gmail account instead.

You need to

• Make sure that your old Google Workspace account is active. The data migration service can't migrate data from a suspended account.
• Turn IMAP on for users. For details, go to Turn POP & IMAP on and off for users.
• If you have 2-Step Verification or single sign-on (SSO) turned on, generate an App Password for the data migration service. You'll use it later in the Google Admin console when you're migrating mail. For details, go to Sign in with App Passwords.

Your users need to

1. In their old Google Workspace account, sign in to Gmail.
2. In the top corner, click Settings See all settings.
3. Click Forwarding and POP/IMAP.
4. Under IMAP access, select Enable IMAP.
5. Under Folder size limits, select Do not limit the number of messages in an IMAP folder (default). 
6. Click Save changes.

   Note: If you saved any changes, you need to repeat step 2 to return to Settings.

7. Click Labels.
8. Make sure that any label that needs to be migrated has the Show in IMAP box checked.

Applies to personal Gmail accounts (ending with @gmail.com or @googlemail.com). 

Note: You can use this option when migrating from an existing Google Workspace account, but you have to authorize each source user separately. Therefore, it isn't recommended.

Your users need to

1. In their old Gmail account, sign in to Gmail.
2. In the top corner, click Settings See all settings.
3. Click Forwarding and POP/IMAP.
4. Under IMAP access, select Enable IMAP.
5. Under Folder size limits, select Do not limit the number of messages in an IMAP folder (default). 
6. Click Save changes.

   Note: If you saved any changes, you need to repeat step 2 to return to Settings.

7. Click Labels.
8. Make sure that any label that needs to be migrated has the Show in IMAP box checked.

Gmail users must also allow the data migration service access to their account. You'll complete this step later when you migrate email to Google Workspace.

Applies to HCL Domino IMAP server (Domino version 8.5.2 and later). 

Step 1: Prepare your mail files and users for IMAP access

1. In the Person document for each user whose mail you want to migrate:
   1. Set the Format preference for incoming mail to Prefers MIME. 
   2. Ensure that all users you want to migrate have an Internet password set in their Person document.

      The data migration service and Domino IMAP service use these passwords for authentication.

2. Enable HCL Notes views for IMAP and folder synchronization.
3. Run the Domino Compact and Fixup tasks against your mail databases.

   Doing so ensures that the On Disk Structure is correct for each database. It also verifies the integrity of the mail prior to the conversion process.

4. Run the mail conversion utility (the Convert task) to enable IMAP-specific features in each mail database.

   The conversion utility sets an option bit in the database indicating that the database is IMAP-enabled.

5. Run the conversion utility a second time using the -h option.

   This step adds IMAP attributes to messages that are already in the mail database at the time of the initial conversion.

6. When the conversion process has completed, verify the "Database is IMAP enabled" message appears in the database properties.

Step 2: Obtain and install a third-party TLS certificate

Set up TLS using a third-party certificate authority on your Domino server. Refer to your HCL documentation for instructions.

Step 3: Enable and start the Domino IMAP server

1. Open the mail server's configuration document in the Domino directory:
   1. Click MIMEConversion Options.
   2. Select Outbound.
2. In the Message content field, select from Notes to HTML.
3. To open your server document in the Domino directory, click PortsInternet PortsMail.
4. On both the TCP/IP and TLS ports, enable the IMAP service.
5. Ensure your firewall allows traffic to flow on ports 143 and 993.
6. If the IMAP service doesn't automatically load when you start your Domino server, open your server console and enter: load imap.

Next step

Follow the steps in Migrate email to Google Workspace.

Recommendations

• Run a test migration before migrating data. 
• Ensure your server gets connections from Google IP address ranges.
• For details on setting up your Domino server, consult your Domino documentation.