Skip to main content

How to migrate Gmail (IMAP) to Google Workspace

Angus
Updated

Switching from *@gmail.com to person@company.com.au (Google Workspace)?  

Important Update: Starting January 2025, Less Secure Apps access will no longer be supported for Google Workspace accounts. This affects the IMAP migration method described below.

For migrations after January 2025, please use the Gmail API to Google Workspace API Migration Guide instead.

For the source, we're using IMAP. 

For the destination, G Suite (API).

How to Migrate Gmail to Google Workspace

  1. Get credentials from customer for source consumer gmail account.
  2. In source gmail account:
     - turn on Less Secure Access (Note: This option will not be available after January 2025)
     - turn on IMAP
     - if 2-step verification in  is enabled, get an app password to use instead of gmail password
  3. Setup credentials for G Suite API destination 
  4. Setup mailbox migration project in Bittitan Migration Wiz
  5. In the migration wiz project:
    1. Do the trial migration to confirm folders are mapping correctly to destination.
    2. Do the pre-stage migration (migrates everything except last 30 days).
  6. In domain management (wherever name servers are) cutover MX records to Google Workspace
  7. In migration wiz project, start the full migration
  8. Turn on forwarding from consumer gmail to workspace account.
  9. Advise staff:
    - to use new Google Workspace account (share credentials
    - to send an email to customers from gmail announcing new email account e.g. "Hello, we have switched our email account to person@company.com.au. We have forwarding turned on, so emails will be forwarded to our new account. Please update your records."

Troubleshooting login issue with source gmail 

Set up IMAP and change your SMTP settings to read Gmail messages in other mail clients, like Microsoft Outlook and Apple Mail. When you use IMAP, you can read your Gmail messages on multiple devices, and messages are synced in real time. You can also read Gmail messages using POP.

Note: To avoid temporarily locking yourself out of your account, make sure you don't exceed 2500 MB per day for IMAP downloads and 500 MB per day for IMAP uploads. If you're setting up a single IMAP account on multiple computers, try taking a break between each setup.

Set up IMAP

Step 1: Check that IMAP is turned on

  1. On your computer, open Gmail.
  2. In the top right, click Settings Settings and then See all  settings.
  3. Click the Forwarding and POP/IMAP tab.
  4. In the "IMAP access" section, select Enable IMAP.
  5. Click Save Changes.

Step 2: Change SMTP & other settings in your email client

Use the table below to update your client with the correct information. For help updating your settings, search your email client's Help Center for instructions on setting up IMAP.

Incoming Mail (IMAP) Server

imap.gmail.com

Requires SSL: Yes

Port: 993
Outgoing Mail (SMTP) Server

smtp.gmail.com

Requires SSL: Yes

Requires TLS: Yes (if available)

Requires Authentication: Yes

Port for SSL: 465

Port for TLS/STARTTLS: 587
Full Name or Display Name Your name
Account Name, User name, or Email address Your full email address
Password Your Gmail password

Troubleshoot problems

I can't sign in to my email client

If you can't sign in to your email client, you might see one of these errors:

  • "Username and password not accepted"
  • "Invalid credentials"
  • You're asked to enter your username and password over and over

Step 1: Check your password

If you have these problems or can’t sign in, first check to make sure you’re using the right password.

Step 2: Try these troubleshooting steps

  • Update your email client to the latest version.
  • Use an App Password: If you use 2-Step Verification, try signing in with an App Password.
    • Important: If you sign in with OAuth, use your regular Google password.
  • Allow less secure apps: If you don't use 2-Step Verification, you might need to allow less secure apps to access your account.
  • If you recently changed your Gmail password, you might need to re-enter your Gmail account information or completely repeat your Gmail account setup on your other email client.
  • If the tips above didn't help, visit https://www.google.com/accounts/DisplayUnlockCaptcha and follow the steps on the page.
  • The email client's sign-in method might be insecure. Try signing in directly on the Gmail app.
  • Make sure your mail app isn't set to check for new email too frequently. If your mail app checks for new messages more than once every 10 minutes, the app’s access to your account could be blocked.
"Too many simultaneous connections" error

You can only use 15 IMAP connections per account. If you have many email clients getting messages from Gmail at the same time, you may see the "Too many simultaneous connections" error.

If you use multiple email clients or devices for the same Gmail account, try closing or signing out of some.

Security certificate CN error

Try the options below if you see this error: "The server you are connected to is using a security certificate that could not be verified. The certificate's CN name does not match the passed value."

  • Make sure you've set up your mail client for IMAP and not POP.
  • Check your Incoming Server setting to make sure it says imap.gmail.com and not pop.gmail.com.
My email client is crashing, or emails are taking too long to download

You might be downloading too many emails at one time.

To fix this:

  • Update your IMAP settings so you don't sync certain folders.
  • Remove your Gmail account from your email client, then try adding it again.
  • In your Gmail IMAP settings, set IMAP to only sync folders with 10,000 emails or fewer.

Comments

0 comments

Article is closed for comments.