Zimbra to Microsoft 365 Migration Made Easy

Outgrown Zimbra? Migrate to Microsoft 365 for superior scalability and integrated tools like Teams. This guide details reasons, pre-migration steps for error-free data movement, a complex manual TGZ-to-PST process, and an automated tool (SysTools) for a faster, simpler Zimbra to Microsoft 365 mailbox migration.

For IT Directors, server admins, and even users who rely on Zimbra, it can start to feel that the email management entity is now a shadow of its former self. It’s not that Zimbra has not received updates or deteriorated in quality; it’s the sheer demand of modern business environments that has outpaced what Zimbra is capable of delivering. One of the ways in which this limitation can be resolved is by conducting a Zimbra to Microsoft 365 migration.

This is because Microsoft 365 outright eliminates many of the issues that are holding Zimbra back.

One characteristic of Zimbra is its minimalistic structure. Yet it backfires when dealing with complicated business scenarios. However, when we look at M365 Business suite we witness the presence of a multitude of applications(Teams, SharePoint, etc) backed by an industry-leading reputation. All of this makes Microsoft 365 an easy choice over its other counterparts like Zimbra.

So, join us as we take you through the entire migration process, starting with the causes of migration.

Reasons Why Zimbra to Office 365 Migration Takes Place in Organizations

The following are just few of the many different reasons that make a case for switching to Microsoft 365 from a old Zimb:

• Zimbra falls short in providing its services if a network is absent. Whereas Microsoft 365, although cloud-based, still offers offline capability.
• Small organizations that operate locally may use Zimbra. However, companies that plan to expand their reach need to leave behind the outdated platform and use Microsoft 365.
• Zimbra also lacks the presence of other in-house apps like Teams, OneDrive, etc, available with the Microsoft 365 suite.

It is now all but clear that Microsoft 365 provides superior scalability and diverse tools, along with an upgraded email service. Before we undertake the manual process of Zimbra to Microsoft 365 Migration, some prerequisites must be satisfied. Let’s look at what they are and how to complete them.

The Premigration Steps for an Error-Free Data Movement

These are the steps any admin must complete before transferring mailboxes.

1. Ensure admin access at both source and destination.
   • Global administrator rights in Zimbra
   • Organization management role in Microsoft 365.
2. Create a CSV file for exporting user data.
   • In the Zimbra Admin pane, expand the search toolbar, then press ‘Accounts’.
   • Type the domain name & download it using the option on the search toolbar.
3. Log in to the Microsoft 365 admin center, create a space for users and assign licenses.
4. Set up either a public mailbox or an email archive mailbox based on the location you want your data to be in.
5. Keep a tab on the network connection speed and check if the bandwidth is sufficient to handle the transfer or not.
6. Provide the end users and stakeholders with details of the migration plan and keep them in the loop
7. Conduct a trial migration prior to beginning the genuine one to make sure everything is migrating to the right place.

Issues like invalid permissions, data loss, and connection breakdown can be avoided altogether if proper precautions are put in place. Now we can proceed with the actual method

Manual Archive Procedure for Zimbra to Microsoft 365 Migration

Use the following steps to move Zimbra data to the Microsoft 365 environment.

Step 1. Unzip the TDZ file

Step 2. Convert the Email (.eml), Calendar (.ical), Contacts, (.vcf) file into PST.

Step 3. Upload the Converted PST to the Microsoft 365 Account via Outlook client (at user level) or admins can do the following:

• Obtain a copy of SAS (Shared Access Signature) in the network upload section of the Microsoft Compliance Center.
• Then, acquire the Azure AZ Copy tool & utilize it to upload the PST from your local device.
• In the Microsoft Admin Centre, start the PST import job operation via a mapping file.

Migrate from Zimbra to Office 365 Via IMAP Transfer

Step 1: Identify Zimbra Server Name.

Admins or even users can find the name via email client. This name is what allows Office 365 server to understand where the data is coming from.

Step 2: Make Source and Target Mailbox List.

This is a CSV file that contains a list of mailboxes for Zimbra mail migration to Office 365.

• In Zimbra.
  • Access the server via SSH (or other secure methods) as the zimbra admin.
  • Run the command

    zmprov -l gaa

  • Copy-paste the result into a spreadsheet and convert it into a CSV file.
• Within Microsoft 365 admin center.
  • Open Users > Select Active users.
  • Select the user list and paste it in a spreadsheet like Excel.
  • Fill email address and password for every mailbox in the list and Save.

Step 3: Connect Office 365 to Zimbra email system.

• Go to EAC (More Admin Centers > Exchange)
• Under Recipients → Select Migration → Toggle More →Open Migration endpoints.
• Click New.
• Pick IMAP as the migration endpoint type..
• Inside the IMAP migration configuration page, enter Zimbra IMAP server information.
• Click Next.
• Within “Enter general information page”, type a Migration endpoint name, but don’t change other values.
• Press Create (This makes the migration endpoint).

Step 4: Build a O365 Migration Batch

• In EAC, go to Migration > Add migration batch.
• Name the batch (Zimbra to O365), select Migrate to Exchange Online, then Next.
• Select IMAP migration, then Next.
• Confirm prerequisites, then Next.
• Select a migration endpoint, then Next.
• Download the user CSV template, add user info, import the CSV, then Next.
• Configure filtering options (if any), then Next.
• Set scheduling options (reporting, start/end modes).
• Click Save, then Done.

These steps may feel complicated, but users need not fret, as we have a simplified way of achieving the task at hand.

Post Migration Tasks

Asks users to do data verification for each workload involved in migration.

• Start by checking all historical Email messages.
• Then, see if all the contacts are there or not.
• Continue to check whether Calendars entries and other meta details are correct.
• Verify that Zimbra Briefcase files are accessible in their OneDrive counterparts.

Apart from data level checks, mailbox functionality should also be verified. That means admins have to

• Update MX Records to point to Microsoft 365 and correctly route all new emails.
• Configure Email Authentication via SPF, DKIM, and DMARC records for secure deliverability.
• Update Email Clients (Optional). Although users can continue using their existing email client, Outlook provides many advantages and native compatibility with the new Exchange Online account, so switching this is also better.
• Once fully satisfied with the Zimbra to Office 365 migration, decommission the old Zimbra system.

End Note

The discussion on Zimbra to Microsoft 365 Migration is now complete. We covered everything from the reasons to the manual methods. Moreover, to fast-track the data transfer automated utility is presented too. Now it is up to the user which method they want for fast and secure mailbox migration.