IONOS to Office 365 Email Migration

Why Organizations Move IONOS Email to Microsoft 365

1. Exchange Online administration: Centralize users, licenses, mailbox access, retention, security, and mail flow in Microsoft 365.
2. Microsoft 365 collaboration: Use Exchange Online alongside Teams, SharePoint, OneDrive, and Microsoft 365 applications. The IMAP migration itself transfers email only.
3. Staged cutover: Run an initial mailbox copy and follow-up incremental passes before changing production mail DNS.
4. Separate email from other services: Keep other IONOS services unchanged while Microsoft 365 becomes the mail destination if that matches the organization's plan.

Let’s explore the simple and effective solutions available to migrate emails from IONOS to Office 365 effortlessly.

1. Plan to Migrate email from IONOS to Office 365

   • Inventory IONOS Mail users, mailbox sizes, folders, aliases, and active users.
   • Confirm the source is IONOS Mail rather than IONOS Microsoft Exchange.
   • For IONOS Mail, use imap.ionos.com, port 993, SSL/TLS, and the full mailbox email address.
   • Create/provision Microsoft 365 target mailboxes and assign licenses.
   • Add and verify the custom domain in Microsoft 365 if it will continue to be used for email.
   • Review source limits, Microsoft 365 throttling, message-size policies, and bandwidth.
   • Run a pilot mailbox and verify the target before production migration.

2. Pre-migration activities to Migrate email from IONOS to Office 365

   IONOS Mail source

   • Incoming IMAP server: imap.ionos.com.
   • IMAP port: 993.
   • Encryption: SSL/TLS.
   • Username: the full IONOS email address.
   • Password: the password assigned to the IONOS mailbox.
   • For bulk migration, prepare the EdbMails CSV and validate a small test set first.

   Microsoft 365 target

   • Create/provision the required target mailboxes and assign licenses.
   • Add and verify the custom domain if Microsoft 365 will receive production mail.
   • Use the current EdbMails OAuth-based Microsoft 365 target connection and run a pilot before production migration.

3. Steps to Migrate from IONOS to Office 365

   • Step 1: Download and install EdbMails IMAP migration software

     • Download EdbMails and install the application on any computer running on Windows OS that is connected to the source and target environment.

        See a detailed list of EdbMails system requirements for IMAP migration.

       

     • Start the EdbMails application on your computer.
     • Provide your registered email address and password, then click ‘Login’. If you are new to EdbMails, select ‘Start Your Free Trial’ to continue with the trial edition.
        Note: The EdbMails IMAP trial lets you evaluate the workflow and migrate up to 30 items from each folder. To migrate all eligible items for licensed mailboxes, purchase the required IMAP migration license.

        View current IMAP migration pricing.

       

     • Select the option ‘IMAP (Gmail, Outlook & more) Migration’.

       

     • Select ‘IMAP to Office 365 Migration’.

       

     • You can proceed with the default job name automatically assigned by EdbMails or click ‘New Job’ to create a custom name. Assigning a clear job name helps you easily identify and organize multiple migration tasks, making overall migration management more efficient.

       

   • Step 2: Connect to source IONOS server

     • To connect a single IONOS mailbox, select ‘Single User / Account Migration’, choose ‘Connect to IMAP Server’, and click ‘Next’.

       

     • For standard IONOS Mail, enter imap.ionos.com as the IMAP server, use port 993 with SSL/TLS, and provide the full IONOS email address and mailbox password.
     • Fill the user’s email login credentials to create a secure and authenticated connection for the migration process.
     • Click the ‘Login’ button.

       

     • To connect multiple IONOS mailboxes, select ‘Multiple (Bulk) Users/Accounts Migration’, choose ‘Connect to IMAP Server’, and click ‘Next’.
     • Then proceed by clicking ‘Next’.

       

     • Click ‘IMAP Migration CSV File’. It will load the sample CSV file to your local drive.

       

     • Open the CSV file and fill in the necessary details, including the email address, password, IMAP server hostname, and port number for each mailbox. After completing the entries, save the file to proceed with the migration.

       

     • Once you've made the necessary changes to the CSV file, save and close it.
     • Then, click the 'Load Modified CSV File' button, open the CSV file and click ‘Next’ to proceed.

       

   • Step 3: Select source IONOS server mailboxes

     • Select the mailboxes or specific folders you want to migrate, then click ‘Next’ to proceed with the migration process.

       

   • Step 4: Connect to target Office 365

     • Click the ‘Add New Connection’ button to establish a new connection to the target Office 365. To use the previous connection, select it from the connection list and click the ‘Connect to Existing’ button to proceed.

       

     • Select the Microsoft 365 mailbox connection option appropriate for the destination mailbox used for this IMAP email migration, then continue with the current OAuth-based authentication workflow.
     • Click ‘Next’ to proceed with the setup.

       

     • Select any of the available options to establish a secure connection using OAuth 2.0 modern authentication.
     • Choose Auto Registration for a quick setup. Sign in with a Global Admin account and grant the required permissions to automatically register the application in Azure AD.
     • Alternatively, select Manual Registration if you prefer to enter the Azure AD application details yourself. This method supports both Global Admin accounts and accounts with Full Access permissions.
     • Click ‘Login’ to proceed.

       

     • Sign in through the official Microsoft login page to authenticate your account and proceed with the migration.

       

     • Load Mailboxes Automatically: Use the automatic option to retrieve available target mailboxes through the current EdbMails Microsoft 365 connection. If every required mailbox is not returned, use the supported CSV-loading option and verify the destination mailbox list before continuing.
     • Click the ‘Next’ button to continue.

       

   • Step 5: IONOS to Office 365 mailboxes mapping

     • Choose the appropriate mailbox and folder mapping option based on your migration preferences.

       

     • Where supported and selected, EdbMails can assist with target mailbox creation and automatic mapping. Verify Microsoft 365 licensing and review every source-to-target mailbox mapping before starting the production migration.

       

   • Step 6: Start IONOS to Office 365 migration

     • After mapping the mailboxes, click the ‘Start Migration’ button to initiate the migration process.

       

     • Click the ‘View Log’ button to view the migration report, which includes mapping details and the total count of migrated emails.

       

     • Login to your target server and verify the items.

4. IONOS email to Office 365 Post-migration Tasks

   • Verify the target

     Review migration reports and check representative folders, messages, attachments, item counts, and user access.

   • Update MX/DNS when ready

     If Microsoft 365 becomes the production mail platform, change the required mail DNS records only after target validation.

   • Validate Outlook/client access

     Confirm Microsoft 365 sign-in and Autodiscover behavior and recreate Outlook profiles only where required.

   • Retain the IONOS source during validation

     Keep the old mailboxes available for the agreed transition period before decommissioning them.

5. Troubleshooting Guide for IONOS email to Office 365 Migration

    For troubleshooting, check out our knowledge base articles. If you have additional questions, browse the FAQs or contact our dedicated support team for personalized assistance.