POP/IMAP Migration

Migrating emails from the existing email service to Zoho Mail

IMAP vs POP Migration

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. To know more on which migration would be ideal for your accounts, click here.

Configuration details needed before Migration:

For both POP/ IMAP Migration, the following 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
  • Migration Protocol - Choose if your migration protocol is POP or IMAP.
  • Exclude Folder List - The administrator can exclude some folders like "Spam" to quicken 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 commonly exclude list, which will apply to 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 the 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. 
  • Path Prefix - Some IMAP servers expect the PATH Prefix details for connecting and retrieving emails via IMAP. 
  • Black Out Time - In case there is any known downtime 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 for migration:

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

  1. Login to https://www.zoho.eu/mail
  2. Launch Control Panel, go to Mail Administration, and choose 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 Security type and the port number for migration. 
  7. Select if your migration is going to be done from Gmail or Office 365 or other services. 
  8. Provide the maximum connection limit for your server.
  9. In the Exclude Folder List option, add the list of folders that you want to skip during migration. Enter the names of the folders within double quotes ("Folder1"), in which case only that folder will be excluded. If you want all subfolders under a parent folder to be migrated enter the folder name followed by /* within double quotes ("Folder1/*"). For detailed information on the convention, refer here.
  10. Select Add Migration to save the server details. 
  11. You need to add the account details to be migrated as the next step. 

Source User details for migration:

After you have added the Server details, you will have to add the Account Details. 

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 Add Accounts to add the account details manually. 
  2. Provide the Source username/ Password and the Destination to which the emails should be migrated. 
  3. In the Folder Option, you can choose either the All Folders or Specific Folders option. 
  4. If you choose the All Folders option, in case of IMAP migration, you can choose to skip any folders during migration using the Exclude Folder List option.
  5. The skip folders option will be handy when the admin rerun migrations for the same set of users for some new emails or missed emails. Enter the names of the folders within double quotes ("Folder1"), in which case only that folder will be excluded. If you want all subfolders under a parent folder to be migrated enter the folder name followed by /* within double quotes ("Folder1/*"). For detailed information on the convention, refer here.
  6. If you choose the Folder Specific option, in case of IMAP migration, you can specify the folders that need to be included in the Include Folder List. 
  7. In the Include Folder List, enter the names of the folders within double quotes ("Folder1"), in which case only that folder will be included. If you want all subfolders under a parent folder to be migrated enter the folder name followed by /* within double quotes ("Folder1/*"). For detailed information on the convention, refer here.
  8. Choose if you want to migrate All Mails or those that fall within a specific date range from the Date Range option.
  9. This will be authenticated with the source server provided, once you click Add.

Convention for mentioning folders:

  • In case you want to mention a specific parent folder (E.g. Reports), enter it as "Reports".
  • In case there are multiple subfolders under Reports and you want to mention all the subfolders, enter it as "Reports/*"
  • In case there exists a subfolder under Reports named 2016, and you want to mention this particular subfolder, enter it like this - "Reports/2016". 
  • If you want to mention all the subfolders under Inbox, only the Marketing folder without the subfolders, and a specific subfolder, 2012, alone under the Sales Reports folder to be mentioned, you will have to type the Folder List like this - "Inbox/*", "Marketing", "Sales Reports/2012".

Steps to Import users from CSV file:

Instead of manually adding the users for migration, you can also add the user details to an excel sheet, save it as a CSV file and upload it. The user accounts mentioned in the CSV will be uploaded for migration.

  1. Click the Upload Accounts link in the Migration Accounts page.
  2. The format for entering the User Details in the CSV file will differ according to the type of migration that you've chosen.
  3. In the right pane of the Upload Accounts section, you will find a sample CSV file.
  4. Download the sample file, look up the details, and enter your user details accordingly.
  5. Save it as a CSV file.
  6. Choose the respective file and Click Ok to upload the accounts.
  7. The accounts added will be listed in the section.
  8. You will be able to modify the Server details or the Migration type before you start the migration. 
  9. Check whether all the accounts to be migrated has been listed in Accounts section. 


  • In all migration types, the source account, password, and the destination account details should mandatorily be entered in the CSV file.
  • In case there is an issue while uploading the users, another file with the error details will be downloaded automatically. 
  • Sometimes, there might be an issue with authenticating your source account due to various reasons. For more details, follow this help page.

Start Migration Process

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.You can add multiple migrations from different servers or from the same server for different sets of users to have a phased and planned migration. 

  1. The list of migrations you have added will be listed on the Migrations page.
  2. Click Start link, across the migration you have just added to start the migration. 
  3. The Migration will be scheduled and the status will be 'In Progress' for the migration that is currently running. 
  4. You can view the overall migration status in the listing, and detailed migration status in the Accounts section.
  5. For IMAP Migration, detailed statistics along with folder information will be available. 
  6. Click the count under the Total field to view the detailed information about the folder-wise migration details.
  7. Under each account, the errors, if any, will also be listed with details. Click Failed to view the number of emails not migrated and the reason. 

For more information on reasons for migration failure, follow this help page.


Suspension of Migration

During the process of migration, if the size of the emails migrated in the account, exceeds the allowed storage, the incoming emails may get blocked. Hence to avoid this, if the account reaches 80% of the allowed storage, the migration gets suspended(paused) temporarily. You can create more space either by deleting some of the old or unwanted emails in your previous account or by purchasing additional storage for your Zoho account.

Once you are confident that the account has enough space, you can resume the migration.

Share this post : FacebookTwitter

Still can't find what you're looking for?

Write to us: support@zohomail.com