Pre-requistes for using IMAP to migrate data


Using LegacyFlo, you can migrate email data between two email servers using the IMAP protocol. The steps to use LegacyFlo are as follows:

  1. Preparation
  2. Post requests on LegacyFlo to migrate data

Preparation for All IMAP servers

Before using LegacyFlo confirm the following
  1. The source and destination server types are supported by LegacyFlo
  2. The email are available in the mailboxes hosted on the source server. Email which have been downloaded using the POP protocol and deleted from the server, cannot be migrated using this option.
  3. Your email service provider supports IMAP access to mail boxes
  4. You should have the rights and the capability to reset the passwords on the source and destination server in order to access the mail boxes.
  5. In case of an in-premise setup, you have provisioned sufficient Internet bandwidth. (This will not apply to SkyConnect, Vaultastic, O365, Yahoo or GSuite.)
  6. The source email service provider should allow large email downloaded via IMAP without any throttling. 
  7. If the source or destination server is GSuite or Yahoo, you have configured your email server to allow IMAP access as mentioned in the sections below.

Additional Preparation for GSuite

Before migrating the historical data from GSuite, following settings are required to be configured on GSuite:

  1. Admin should Enable less secure apps to access accounts
  2. Users should enable the access for less secured apps in Gmail Account Setting
  3. Users should confirm the setting in email received from Google Support (Optional)
  4. Configure Gmail for sharing or sync

Step A: Admin should enable less secure apps to access accounts

  1. Sign in to your Google Admin console.
  2. In your Google Admin console, go to Security > Basic settings
  1. Under Less secure apps, select Go to settings for less secure apps
  1. In the sub-window, select the Allow users to manage their access to less secure apps option to allow them to toggle access for less secure apps on or off themselves.

Step B: End users should enable the access for less secured apps in Gmail

  1. Log in to to Gmail account
  2. Go to Google Account > Sign in & Security option
  1. Choose the Apps with account access option
  2. Turn On the option Allow less secure apps

Step C: User should confirm the access

If user receives an an email from Google support with subject Review Blocked sign-in attempt, the user should be asked to do as follows:

  • Open the mail 

  • Click Secure your account

  • Skip all the steps and navigate to Disable access for less secured apps section and  turn On the Access for less secure apps

Step D: Configure Gmail for sharing or sync

IMAP sync of Gmail requires that IMAP is full enabled. And here is how to check if your Gmail has IMAP enabled:

  1. Log into your Gmail account at
  2. Go to your Gmail settings and select “Forwarding and POP/IMAP” (the direct link should be verify the following:
    1. Enable IMAP” should be selected.
    2. Do not limit the number of messages in an IMAP folder” should be selected.
    3. Save the above settings.
  3. Go to the “Labels” tab (the direct link should be:
    1. Verify that “All Mail” have “Show in IMAP” enabled.
    2. If you are syncing emails from a label or sharing a label, you need to ensure that label and all sub-labels in that label have IMAP enabled.

Additional Preparation for Yahoo

Before migrating the historical data from Yahoo, user's on your domain should generate password for imapsync and share it with admin. 

Generate password for imapsync

  1. Login to the Yahoo mail account,
  2. Click on the account name or the avatar and select Account Info
  3. Click on Account security
  4. Turn on Two-step verification
  5. Click on Manage app passwords and generate a specific password for imapsync,
  6. Choose Other app at the bottom and type imapsync as this option is not in the predefined apps.
  7. Use this password with imapsync.