How to Migrate POP Emails to O365 (Exchange Online) Step by Step?

If you are wondering how to migrate POP3 to Office 365, don’t worry, you are neither the first nor alone with nor alone with this query. Thousands of personal and business users have had the same question in the past.

With this guide, they were able to switch away from the archaic Post Office Protocol and make Exchange Online their email communication environment.

We have assembled multiple ways based on your configuration. Plus, we have also highlighted the common problems that users encounter during the migration. On top of all that, you will get a list of best practices that can make the process super smooth.

Before we cover the actual transfer process, let’s start by looking at the most prominent reasons that force users to switch from POP3 to M365.

Why Migrate POP3 to Office 365?

POP3 is an acronym for Post Office Protocol version 3. It is a decades-old set of rules that governs the movement of emails from the server to the user-facing email client.

It works by pulling the email from the server (popping it) and putting it in front of the user. This simple arrangement helped to free the server from unnecessary storage.

However, now servers are much more storage sufficient and no longer have to rely on deletion-based tactics for memory management.

Other than deletion from the server, there were several disadvantages of POP3

• You could only see the emails on one device. This is because once the emails pop server maintains no record.
• Emails were lost permanently if the end user device faced any issues.
• The POP3-style email accounts lack proper calendar, contact, or attachment management.
• Mailbox size was subject to server capacity. So if emails were not popped regularly, there was a risk that email communication could seize.

On the other hand, if you migrate POP3 to Office 365, you can use Exchange Online and get several key advantages.

• Multi-device access via cloud sync. Any change you make on one device is automatically reflected everywhere you have your M365 account.
• You get free access to shared calendars and contacts.
• With an Office 365 account, you get to utilize the full potential of the Microsoft Business Suite with apps like Teams, Word, OneDrive, etc.
• State-of-the-art security and freedom from server management.
• Pay-as-you-go style scalability that works for businesses of all sizes.

POP3 vs Exchange Online: Key Differences Explained

Consider this tabular comparison chart to understand what POP3 lacks that Exchange Online provides.

Feature	POP3 Email	Office 365 (Exchange Online)
Device Sync	❌ No	✅ Yes
Storage	Limited to one device	Cloud, scalable
Collaboration	None	Teams, OneDrive, SharePoint
Security	Basic login only	MFA, encryption, compliance
Management	Manual	Centralized Admin Center

You dont always have to migrate POP3 to Office 365. It is possible to maintain a dual system via an email client, where both the POP3 and Microsoft email systems coexist. However, such a hybrid system causes more problems than it solves. You are still stuck with an insecure Post Office Protocol-style email, vulnerable to MITM attacks. So now that we are sure that this change has to be done, let’s see what options we have.

Single Account POP3 to Office 365 Migration Options

A POP3 to O365 transfer isn’t a straightforward single button press. This is because the fundamental design of Post Office Protocol removes emails from the server and places them into the user’s email client.

So to combat this issue, we have to devise some smart solutions. Like:

Method 1: Set up in Outlook, then drag and drop  

Every modern Windows machine comes with the Outlook client preinstalled, so you might think of using it to migrate POP3 to Office 365. However, if you use it, you might face difficulty in setting up the POP account.

So I recommend that you install a copy of the classic version and attempt the procedure there.

• Connect both your accounts with the respective protocol (i.e., POP and Exchange Online)
• Then click and hold the emails. Then drag and drop them in the intended location.

Method 2. Change POP3 to IMAP, then migrate

Some providers allow the transformation of existing POP3 accounts to IMAP. If you can do so, Microsoft has its own IMAP import mechanism you may use.

This was the option for individuals. Organization-wide change needs the contribution of both users and admin

Step 1: Set up the POP3 Account in Any Email Client

Here we will cover two of the most prevalent email clients.

On Thunderbird (To be done by user)

• Open Thunderbird and click on the Hamburger Menu in the top right corner.
• From the dropdown select new account, then when the panel switches, choose Email.
• A new Mozilla Thunderbird Account Hub box appears, add your name and POP3 email address, then press continue.
• Next screen Thunderbird by default selects IMAP, so change the selection to POP3 and continue.
• Complete the authentication requirements (it may vary based on the source for your POP 3 account)

On Outlook (Use Classic edition) 

• Launch Outlook Client, go to File → Info → Add account.
• The Outlook wizard for setting up a new account will open up. Enter your POP3 email address to add your account. Toggle Advanced options and select “Let me set up my account manually” → Connect.
• Choose the account type POP.
• The dialog POP Account Settings will open up.
• Take the following settings:
  • Incoming mail: Enter pop.server.name with accurate port number and check the option This server requires an encrypted connection (SSL/TLS)
  • Outgoing mail: Enter smtp.server.name with accurate port number and the encryption method STARTTLS (recommended)
• Click on Next.
• A login dialog will open up. Enter your password and click on Connect.

You can use any other email client as well; the steps may vary.

Step 2: Locate and Prepare POP3 Email for Microsoft 365

Whatever email client you use, make sure that you download all the messages.

Those who added emails in the Thunderbird client.

• Open Thunderbird to migrate POP3 to Office 365.
• Click the Hamburger menu button (≡), then go to Help > More Troubleshooting Information.
• On the “Troubleshooting Information” tab, find the “Profile Folder” row under the “Application Basics” section.
• Click the Open Folder button next to it. This will open your profile folder in your file explorer.
• You might have to dig a bit more to locate the actual POP3 mail content (It will be in MBOX format)
• When you find the data, copy it and make a new parent folder. With that parent folder, create a folder with the same name as this particular user. Put the content in this new folder. (To be done by Admin)
• Repeat for all other users in the domain. (Ask users to send the POP3 data)

If you have configured the POP3 email account inside Outlook

• Open Outlook and go to the File tab.
• Click on Account Settings > Account Settings.
• Go to the Data Files tab. This will show a list of your data files.
• Select the data file you want to locate and click Open Folder Location.
• When you find the data, copy it and make a new parent folder. With that parent folder, create a folder with the same name as this particular user. Put the content in this new folder. (To be done by Admin)
• Repeat for all other users in the domain. (Ask users to send the POP3 data).

Now that all the preparation is done, let’s bring these POP3 emails to M365.

Step 3: Professional Tool to Migrate POP3 to Office 365

With the help of the SysTools Office 365 Import Tool, admins can perform a mass transfer of POP3 data into the Microsoft 365 cloud.
Download Purchase

• Launch the tool, select the source format. MBOX(for Thunderbird) or Outlook. Select the Destination as Office 365.
• Mark the Workloads (for MBOX POP3, you will only get the email option; Outlook source file will get Contacts and Calendars too.) Apply Date Filter if needed and click Next.
• On the Source Screen, browse for the parent folder path you prepared in the last step. Validate and Press Next.
• Validate the Office 365 admin credentials and press Next.
• Map the POP3 user accounts in any one of the three available options.
• View the user list, select, prioritize, validate, and import.

This is how you migrate POP3 to Office 365 in bulk.

Best Practices for Migrating POP Emails to Office 365

Always use an Email Backup tool to construct a safe copy of the email data that you are about to migrate.

Use a proper tool to push the POP3 emails to the Microsoft 365 account.

Set up a pilot project to migrate POP3 to Office 365, test out the pathway before fully committing to the transfer process.

Keep users and other stakeholders in the loop and inform them about the shift to avoid confusion and conflicts.

Calculate the total volume of emails that are on the POP3 account and see if enough space is on the Microsoft 365 account. If the answer is no, then you must first set up an archive in Outlook 365

Once fully transitioned to the O365 cloud, decommission the old POP3 servers.

Frequently Asked Questions on POP3 to Exchange Online Migration

Q. Is it possible to directly move all emails from a POP3 account to Microsoft 365?

Yes, Microsoft’s proprietary email client, Outlook (Classic version, not the New Version), allows you to drag and drop emails between POP3 and Exchange One type accounts.
However, Outlook Classic’s end of life is on the horizon. Plus, there aren’t any plans to implement drag and drop between POP3 and Exchange Online in the new version. So use it while you still can.

Q. Has Microsoft stopped support for POP3, so how to migrate POP3 to Office 365?

Yes, Microsoft 365 cloud ended the direct support for the POP3-style authentication method in October of 2020. Since then, Microsoft has gradually moved all of its email systems to more modern and secure alternatives. You can use any of the methods described in this post to migrate.

Q. How do I migrate GoDaddy POP email to Office 365? 

Set up both GoDaddy and M365 email accounts in Outlook Classic, export GoDaddy mail to PST, and Import into M365. You can also switch the  POP account into an IMAP equivalent. GoDaddy allows such a transformation.

Final Thoughts

If your business still operates Post Office Protocol, it’s high time that you understand how to migrate POP3 to Office 365 and perform the necessary transfer.  When you make the switch, you will be able to:

• Access emails anytime, anywhere.
• Enjoy state-of-the-art collaboration.
• Ramp up security with OAuth2

Make your digital infrastructure future-proof. This guide is for everyone, whether you are just an individual email user looking to modernize your experience or an admin who wants to move thousands of users to a more secure platform. Although a manual method to move mailbox data exists, the best way is to utilize the professional import tool.