Migrate emails from Posteo to Office 365

Why should you migrate emails from Posteo to Office 365?

Here are the key reasons why businesses migrate from HostGator to Office 365:

• Enhanced security: Office 365 offers advanced security features like data loss prevention and encryption, providing an extra layer of protection over Posteo’s end-to-end encryption.
• Cloud flexibility: Office 365 allows access to data from anywhere and on any device, offering more flexibility than Posteo.
• Increased storage: Office 365 provides larger storage capacity, enabling businesses to manage and share bigger files with ease.
• Microsoft tool integration: Office 365 integrates with Microsoft tools like Teams, OneDrive, and SharePoint, enhancing productivity and collaboration.
• Continuous updates: Office 365 ensures regular software updates and new features, keeping businesses on the cutting edge of technology.
• Improved collaboration: Office 365 streamlines communication with shared calendars and address books, making it easier to migrate Posteo data.

For these reasons, many organizations choose to migrate from Posteo to Office 365 with the help of EdbMails, ensuring a smooth and secure transition.

1. Posteo email to Office 365 migration plan

   Planning is one of the most important steps before you begin the Posteo email to Office 365 migration. Here is a checklist of points to consider before you migrate.

   • Determine the size of the data and the number of mailboxes you want to migrate.
   • Make a list of all the data and permissions from Posteo email that you want to transfer.
   • Create appropriate user mailboxes on Office 365 and assign licenses to them.
   • Ensure you have enough network capacity and bandwidth to migrate.
   • Communicate the migration plan and flow to your end users.

2. Posteo email to Office 365: Pre-migration activities

   • 1. Find the IMAP server name of your Posteo email server. You can find this information from your server’s dashboard settings or by connecting your email system to Outlook.
     2. Have the users email address, passwords, IMAP hostname and port number.
     3. Create mailboxes on your target Office 365 server. You can choose the option to automatically create target mailboxes in EdbMails. If you prefer to create them manually, refer to the links below.
        1. Add users and assign licenses to Office 365 users
        2. Assign Microsoft 365 licenses to user accounts
     4. If you have a custom email domain from your hosting provider to which you want to migrate and receive emails, you must add and verify the domain on Office 365.
         Steps to add a custom domain to Office 365 and Steps to add DNS records to connect your domain.
     5. Configure Office 365 to send and receive large messages.
         Follow the steps to increase the message size on Office 365 to 150MB and see tips to optimize IMAP migration to Exchange online.

3. Steps to migrate emails from Posteo to Office 365 using EdbMails

   • Step 1: Download and install EdbMails IMAP migration software

     • Begin by downloading EdbMails and installing it on a Windows computer of your choice. The setup is straightforward, and the software is designed to work seamlessly across various Windows environments, allowing you to get started with your email migration in just a few clicks

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

       

     • Launch the application and click 'Login' or 'Start Your Free Trial'.

       

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

       

     • Select ‘IMAP to Office 365 Migration’.

       

     • You can proceed with the default job name assigned by EdbMails, or choose ‘New Job’ to define a custom name. This helps streamline the management of multiple migration tasks and makes individual jobs easier to track and organize.

       

   • Step 2: Connect to the source Posteo email server

     • To migrate a single user from Posteo, enter the Posteo IMAP server address, Port Number (993 for SSL), and the user's login credentials to establish a secure and encrypted connection.

       

     • Choose the correct IMAP host name from the list or manually enter it (e.g., mail.yourdomain.com). Then, fill your email address, password.
     • Click the ‘Login’ button.

       

     • For migrating multiple Posteo mailboxes, select ‘Multiple (Bulk) Users/Accounts Migration’ and click ‘Next’.

       

     • Click ‘Download Sample CSV File’.

       

     • Update the CSV file by entering the necessary details such as the email address, password, server hostname, and port number. Once updated, save the file to apply the changes.

       

     • Once you've made the necessary changes to the CSV file, save and close it.
     • Then, click on the 'Browse CSV File' button, find your updated file, select it, and open it to continue.

       

   • Step 3: Select the source Posteo email 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 server

     • Click ‘Add New Connection’ to set up a new connection to the target Office 365 tenant. If you’ve previously configured a connection, simply select it from the list and click ‘Connect to Existing’ to continue.

       

     • Select the required connection options and click the ‘Next’ button.

       

     • Select the authentication method and click the ‘Login’ button to continue.

       

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

       

     • EdbMails allows you to load mailboxes automatically, which is quick and convenient. However, due to Microsoft API limitations, the automatic method can list up to 100 mailboxes at a time. For larger environments or to include specific mailboxes beyond this limit, you can use the CSV file method to load mailboxes manually—giving you full control over the selection process.
     • Click the ‘Next’ button to continue.

       

   • Step 5: Posteo email to Office 365 mailboxes mapping

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

       

     • You can choose to let EdbMails automatically create mailboxes in Office 365 and map them between the source and target servers. This feature is especially useful for large-scale migrations, saving time, reducing manual effort.

       

   • Step 6: Start Posteo email 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. Posteo email to Office 365 post-migration tasks

   • Step 1: Update the MX records to point to Office 365

     If you have not done this step previously, change the DNS records known as MX records to enable email and receive messages on the target Office 365 server. In addition, configure the Autodiscover record to allow Outlook to connect to the migrated mailboxes.

   • Step 2: Create a new Outlook profile for users in the new domain

     Configure the Outlook profile for each user in your domain if Outlook has problems connecting to Office 365 mailboxes.

5. Posteo email to Office 365 migration troubleshooting

    For troubleshooting, check out our knowledge base articles. If you have additional questions, browse the FAQs or engage with our customer care team for personalized assistance.