I have been using the mac for a long time, earlier I used Entourage as my email client, then came the Outlook 2011 for Mac and now its Outlook 2016 for Mac.

Due to some official guidelines I now need to switch over to Apple Mail. This includes transferring my database from Outlook 2016 Mac to Apple Mail.

As I am completely unaware of this process, I am looking for some help in terms of what I need to do to migrate to Apple Mail. A simple and faster approach will be more preferable.

  • I gotta ask...you have official guidelines that move you away from what is considered the defacto email client?
    – Allan
    Mar 9, 2018 at 12:39

3 Answers 3


There is no easy way to do that.

To import Outlook data in Mail though, most of the time, the easiest is to go through an IMAP or Exchange account configured in both apps.

Copy all the messages you need from Outlook to that account, and it should sync back to Mail.

The other option is already mentioned above to use third-party applications. One application that I felt had some interesting features is OLM Converter Pro.

Its Ultimate version can migrate your Outlook 2016 Mac emails directly to Apple Mail.

Choose your pick wisely. Thanks.

  • I tried both the third party tools mentioned in this thread as I am more comfortable with OLM Converter Pro from Gladwev. I found other manual methods completely useless. Mar 15, 2018 at 11:07

I will be honest upfront, without paid software this will be next to impossible to achieve, I therefore recommend that you stay with Outlook 2016 for Mac and save yourself the trouble and expense. Last time I checked, Outlook 2016 for Mac meets all "Official Guidelines" in he industry, hence is compliant with them. But since you ask, let's move forward.

You are fortunate in that you already have all your mail on the same mac and do not need to deal with a device-to-device data transfer. If your Outlook 2016 would have been on a Windows machine, transferring to Apple Mail would have been a challenge in itself, but lets not worry about that as this involves a few steps too, due to incompatible and proprietary mail databases/formats.

Assumption: I am assuming that you run the latest and greatest macOS High Sierra.

Verify your export options

  1. Open Outlook 2016 for Mac
  2. Go to: File > Export...
  3. In High Sierra an export selection (i.e. Mail, Calendar etc.) windows pops up, look at the title and check if it contains Export to Archive File (.olm)
    It means that the final format you get out of Outlook 2016 for Mac will be a .olm file.

Check your import options

  1. Open Apple Mail
  2. Go to: File > Import Mailboxes...
  3. You should see two options, either Apple Mail (used when you transfer from another Apple Mail - i.e. from another computer or account etc.) and Files in mbox format. This is the option you will have to use to import into Apple Mail.

So far, what we know is the format is at each end. We use Outlook 2016 for Mac to export a .olm file, which we somehow have to turn into a .mbox format to be imported into Apple Mail.

What do we use?
I recommend you check out OLM Exporter (ca. $9.40USD) to do the conversion from .olm to .mbox efficiently. Simply feed it the Outlook export (.olm file) and let it create the .mbox which you can import into Apple Mail.

The .olm files contains all the options you selected upon exporting from Outlook (i.e. Mail, Calendar etc.) however, an .mbox file is (as the name may suggest) a message box so it contains emails only. When using the OLM Exporter, seperate files will be created for any non-mail items you selected upon export (such as .ics for Calander entries or .vcf for contacts. These can easily be imported into their respective mac components. Should they already exist (since the data came from the same mac), you will need to verify the obvious things like contact duplicates.

Being in the IT sector, I deal with this task on a regular basis and hope my answer added something valuable instead of the typical "google is your friend" response. I know this can be difficult to get your head around at first, but it is relatively easy once you have the process down. Let me know how you get on with the mail migration as I would be interested in following up with you about this.


Launch Outlook, select a mailbox that you’d like to move to Mail, and drag it to the desktop. Doing this creates an mbox file (a file format that Mail can import). Repeat this process for all the mailboxes that you wish to import and then place the mbox files into a single folder.

When you’re finished, launch Mail and choose File > Import Mailboxes. A window appears that asks you to choose a source to import data from. Select Files in mbox format and click Continue. A sheet will appear. Use it to navigate to the folder you created for your mbox files and click Choose.

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In Mail, choose to import the mbox files you dragged from Outlook. In the resulting window you’ll see all the mbox files it contains, each with a checkmark next to it. If you don’t wish to import messages from a particular mbox, just uncheck it. Click Continue and the messages within the checked mbox files will be imported into Mail. As Mail will tell you, you’ll find the messages inside an Import folder within its list of mailboxes.

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