Office 365 e-mail migration from Thunderbird

I have set up a new Office 365 account for my domain.
Previously the e-mail was on IMAP.

Having set up the accounts on 365 I want to repopulate the e-mail folders for each user.

I have backups for the Windows users with MozBackup and the Mac users in Outlook OLT files.

365 doesn';t seem to recognise these backups to import the data.

I read what I could copy and paste/drag and drop them within Thunderbird into the new account.
However whenever I do then en-masse I get the following error?

The current command did not succeed. The mail sevrer for accounts X@Y.Z reponded [TRYCREATE] Folder is not found.

What's the workaround?
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Tim EdwardsIT Team Lead - Unified Communications & CollaborationCommented:
Here is one way of doing:

Migrating emails from one email client to another or Office 365 is a complex task that requires a lot of time and investment. In the case of Thunderbird, there are no direct methods to migrate MBOX files (used by Thunderbird) to Office365. However, you could export MBOX files to Office 365 in a two-step procedure. For this, you require to move MBOX emails to Outlook and then import them to Office 365. But this manual method is effective only when you require exporting a limited number of emails from MBOX to Office365. Here is how you can succeed in migrating MBOX data from Thunderbird to Office 365.

In Mozilla Thunderbird, open the folder containing the required emails.
Select the required messages, and then select Save As option from context menu.
Browse the destination folder on the system, and save.
Now open MS Outlook, and create a new folder.
Drag the emails from the system folder to the new Outlook folder.

If needed, you can preview the emails in Outlook. The next step is to upload the Outlook PST files to Office 365 with the help of "Office 365 Import Service". You will need to use a tool named 'Microsoft Azure AZCopy Tool' that will help to upload the PST. The steps are given below in brief:

Share your PST folder over the network.
Install the “Microsoft Azure Storage Tools” (you can download it from the site).
Launch the tool, and get the unique network URL and key for uploading.
Use azcopy.exe to upload the PST files.
Use the Microsoft recommended format to create a mapping file.
Finally, import the PST file data into Office 365
edhastedAuthor Commented:
I am working my way throught this and hope to give an update. Many thanks for your comprehensive noutes.
Tej Pratap Shukla ~DexterServer AdministratorCommented:
The steps mentioned by Tim are correct. But, you can try a quicker solution / automated solution for your query.
You can follow the steps given in the link below:

First, convert MBOX to PST file and then import the resultant PST file into Office 365 in just a few clicks.

I have used this technique. I hope it works for you too!
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edhastedAuthor Commented:
Apologies for the delay in resolving this question but this has taken time.

It is perverse that in 2017 their is no bullet proof mechansim to migrate data between two stallwart e-mail products: Outlook and Thunderbird.

Can I offer the following advice?

  • Make sure you have a tested backup of your original system.
  • Do not delete or deactivate the original e-mail system until you are 200% all the data has been copied over and working completely.

If you are migrating from Thunderbird to Office 365 I would suggest you point Outlook at the original host system and make a .PST backup as well as a Mozbackup, or whatever.

Microsoft on-line do provide IMAP/POP to 365 importers and listed above are other examples and approaches of making this work. The problem is they often don't. I couldn't pull the data from my IMAP mail server into 365. The problem is that there is no such thing as a template POP/IMAP or Exchange server. Each one is likely to be configured ever so differently. And most e-mail data structures are Byzantine. Read the Microsoft PST data structure guide if you don't believe me...

My approach would be as follows:

  • Try and use the inbuilt tools in Office 365.
  • Failing that create the new account and try and copy and paste the data over. If this only partially works try the commented suggestions against the original question.
  • And failing that copy the data, folder by folder. This is what I ended up doing (9GB data/2,000 folders). Excpetionally tedious but it had to be done. Something throws the copy, attachenets, unread messages. It's very odd and inconsistent. Sometimes you can copy very complex folder structures without issue and other times you can't even copy the contents of a folder with a single message in it. As you go check and double check that the number of messages (and content) in each folder and make sure they match.

Eventually the task will be done.

Do not delete the original fle system until you are beyond certain that everything (contacts, lookups, calendar) is copied and working.

Good luck.
tabby smithCommented:
Most popular MBOX to PST Converter Software application for converting MBOX files of these email clients such as Entourage, Netscape, Poco male, Spicebird, Apple Mail, Postbox, Mac mail, seaMonkey, Opera mail into Outlook PST format.The software efficiently scans mailboxes of these mail clients and transfers all emails from MBOX files to equivalent Outlook PST files.It provides you with a stop solution for successful conversion of MBOX files into Apple Mail, Entourage, Thunderbird or Power mail in Outlook PST file created importable perform.

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Geeta MalikTechnical Content DeveloperCommented:
@Tej Pratap Shukla ~Dexter,   Converting Thunderbird mailboxes to PST then importing PST to Office 2016 with two different tools will be time consuming task. I have found many other solutions which allows importing Thunderbird mbox files directly into Office 365 mailbox which are also cost effective such as: transend and MailsDaddy MBOX to Office 365 migration tool etc. One can use these appropriate solution for migrating Thunderbird mail data to Office 365 platform.

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Geeta MalikTechnical Content DeveloperCommented:
No new comments in last few days. I think this question has been solved now.
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