Migrating emails from the existing email service to Zoho Mail

Email Migration

Once you have decided to switch your email hosting service to Zoho Mail, you can easiy migrate your legacy emails to Zoho Mail from your current server. IMAP Migration is the most recommended method to migrate the emails, which makes it easier for the users to continue from where they left without impacting their productivity. 

You can also migrate via POP retrieval. 

In case you have your email data in an Exchange Server (without IMAP support) or in the format of PST files, you can make use of the Exchange Migration Wizard to migrate the emails. The Exchange Migration Wizard migrates emails from PST/ EML or directly from the Inhouse or Hosted Exchange environments. 

Advantages of IMAP Migration over POP

If your emails are in a cloud hosted email service like Google Apps or Yahoo or any other cloud email server which support IMAP Access, you can perform a server to server migration via IMAP from the Control Panel. 

Zoho Mail supports both IMAP and POP Migration, but IMAP Migration has more advantages compared to the POP Migration.

IMAP MigratoinPOP Migration
Folder details are migrated.POP does not support Folder based migration. All emails are migrated to Inbox.

Email State (Read/ Unread) are maintained.


The emails retrieved as 'Unread' via POP .

Multiple Client support:

  • Emails are migrated even if accessed by other clients.
  • The emails are synced in multiple clients with state maintenance
  • The emails available in the source mailbox is synced along with folder and state information.
  • The emails sent by other clients are synced via IMAP.

Only Single Client support:

  • If there are multiple client requests, the email is provided only to a single client.
  • The emails retrieved via POP already are not available for migration 
  • The emails sent by other clients will not be migrated, as it is not supported by POP Servers
The migration is generally fast, and the migration info is detailed.The migration via POP is slower than IMAP Migration.
Specific failures in migration can be tracked and corrected.The failure information in POP is not specific and will be obscure.


Details Required before Migration:

For both POP/ IMAP Migration, the follwing details are required. 

  • Name of the Server - Hostname of the IMAP Server or the POP Server from which the migration needs to initiated
  • Server Port - For source Server standard ports for SSL and Non SSL are supported. 
    • Supported ports for IMAP - 143 (Non SSL), 993 (SSL) 
    • Supported ports for POP - 110 (Non SSL), 995 (SSL) 
  • SSL Type - Only Trusted Certificates are supported. Self Signed SSL certificates are not supported due to security reasons
  • Source User Names and Passwords for the user accounts - Make sure that the source accounts have IMAP access turned On. 
  • Exclude Folder List - The  administrator can exclude some folders like "Spam" to qiucken the migration process. Further they can ask the users to create a common folder and move the emails that need not be migrated. This folder can be provided in the common exclude list, which will apply for all users. 
  • Maximum Connection Limit - The maximum connection limit is the number of maximum connections accepted by the server at a given time. For example, if you provide 5 as maximum connection limit, when the migration is started, the migration process will be started simultaneously for 5 users. The migration process will be faster when there are parallel migrations happening between the servers. 
  • IMAP Path Prefix : Some IMAP server expect the PATH Prefix details for connecting and retrieving emails via IMAP. 
  • Black Out Time - In case there is any known down time for the server or particular times of the week during which the server is overloaded, specify the Day of the week, Time in 24 hour format (From 'x' hours to 'y' hours) and the corresponding Timezone. The migration would be paused during the specified time duration to avoid any migration failures due to that. The Blackout Time and Timezone are applicable, only if there are any predetermined Time Intervals, during which the migration should be paused. 

Source Server Details

To add a new migration, you need to add the source server from which the emails should be migrated. You can also perform migration in batches, and also from different servers if you have multiple domains hosted with different providers and want to migrate everything to Zoho Mail. 

  1. Log in to https://www.zoho.com/mail
  2. Launch Control Panel » Mail Administration » Email Migration
  3. Select Add Migration, to provide server details for migration
  4. Provide a title for the migration
  5. Select the Migration Protocol as IMAP or POP based on your preference. 
  6. Provide the Host-Name of the server , the SSL type and the port number for migration. 
  7. Provide the maximum connection limit for your server.
  8. Exclude Folder ist - The list of folders that need not be migrated during the migration. 
  9. Select Add Migration to save the server details. 
  10. You will be taken back to the Migration Home page. 
  11. You need to add the account details to be migrated as the next step. 

Source Details for Migration 

After you have added the Server details, you will be taken back the Migration Home page. Click the Migration, to add the source accounts to be migrated. 

You can add the accounts manually or import the details from a CSV file. However, make sure that you have the source and the destination account details ready. For each user added, the source credentials are checked with the server and the user gets added only if the source authentication is successful. 

Steps to add user accounts for Migration:

  1. Select the Migration Name to which you want to add the source and destination details. 
  2. Select Add Accounts to add the account details manually
  3. Provide the Source username/ Password and the Destination to which the emails should be migrated to. 
  4. In case of IMAP migration, you can choose to skip any folders during migration. 
  5. This will be authenticated with the source server provided, once you click Add.

Steps to Import users from CSV file:

Prepare an excel file or a Zoho Sheet with the headers Source, Password, Destination. You can optionally include a column Priority, which specifies the order in which users accounts needs to be migrated.

Fill in the details under the respective columns for the user accounts to be migrated.

Save the file as a CSV file.

Click Upload Accounts link in the Migration Accounts page.

Choose the respective file and Click Ok to upload the accounts.

The accounts added will be listed in the section.

You can modify the Server Details, if any changes are needed, before you start the migration.

Check whether all the Accounts to be migrated has been listed in this section

Start the Migration

In the Control Panel, navigate to Migration under Mail Administration. Ensure that the source passwords are not changed after adding the users for migration. The password should be the same until the entire migration process is completed.

  1. In the Migration Page, the migrations you have added will be listed. 
  2. Click 'Start' to begin the listed Migration
  3. The Migration will be scheduled and the status will be available. 
  4. You can click the Migration to view the migration progress for each of the account. 
  5. In case of IMAP, detailed migration stats will be available, along with the folder details and the details of errors, if any. 
  6. In case there are any errors encountered during the Migration Process, it will be displayed in the status. You can get more details in the Migration Accounts page.
  7. A notification Email will be sent to the users in their destination Email Address specified, on successful completion of corresponding Migration.