Moving OLM files that are larger than 50GB is more complicated than regular export processes. To work, the process needs to be planned well and the right approach and system optimization. Evidence shows that directly converting the huge file will likely cause the system to stall, the program to break, and the PST file to be damaged. This problem happens a lot because users treat large files the same way they treat little ones. Depending on what it needs, large-scale data migration needs to be done in different ways. The blog shows you how to safely convert an OLM file to Outlook PST, which keeps your data safe and prevents crashes.
Why Large OLM Files Often Crash During Conversion
When you convert a large OLM file, your computer has to handle a lot of data all at once. This puts a lot of stress on the performance of the RAM, CPU, and hard disk.
Some of the most prevalent reasons for crashes are:
- Putting the whole file into memory
- Slow read/write speed on the hard disk (particularly on a hard drive).
- Outlook can't handle PST files because they are too big.
- While converting to an OLM file, you can run other programs.
Each of these problems will make the system unstable and could cause it to freeze while the conversion is going on.
The Right Strategy: Don't Change Everything All at Once
The worst thing you can do is try to convert the whole 50GB file at once. This almost invariably ends in failure.
Breaking the task up into smaller pieces is a better way to go. The system works better, and the chance of crashing goes down a lot when you process data in pieces.
To get better results, you should:
- Split the OLM file into tiny parts, each 5GB to 10GB.
- Change one part at a time instead of all the data.
- If you can, only look at the key folders.
This approach is quite popular for moving real-world data since it makes the process stable and easy to handle.
How to Change Mac Outlook OLM files to PST (Using IMAP Sync)
This method works by syncing your Mac Outlook data with an email server (like Gmail) and then exporting it from Windows Outlook to PST.
Step 1: Open the OLM file in Outlook for Mac
To start, open Outlook on your Mac.
- Open the File menu and choose Import.
- Choose your OLM file
- Import all of the data from your mailbox, like emails, contacts, and so on.
After that, you will be able to see your OLM data on Mac Outlook.
Step 2: Set up an IMAP email account
You need an email account, like Gmail, to operate as a bridge now.
- Click on Tools and then Accounts.
- Add your Gmail account (or any other IMAP account).
- Log in and finish setting up.
- Check your email account settings to see if IMAP is turned on.
Step 3: Put OLM Data on Your IMAP Account
This is the most important phase.
- Make folders in your IMAP account
- You can move emails from imported OLM folders to IMAP folders by dragging and dropping them.
⚠️ Important:
If you upload all of your data at once, synchronizing might not work.
Step 4: Wait for the sync to finish
Outlook will now start sending data to the email server.
- This could take hours or even days (for big files).
- Make sure your internet connection is reliable.
- Don't close Outlook while it's syncing.
Step 5: Set up the same account in Outlook for Windows
Change to your Windows PC.
- Launch Outlook
- Add the same email account for IMAP
- Allow all data to sync completely.
Your OLM data will now show up in Outlook for Windows.
Step 6: Move IMAP data to PST
After the sync is done:
- Click on File, then Open & Export, and then Import/Export.
- Select Export to a file
- Choose the Outlook Data File (.pst) option.
- Choose directories and export.
The PST file you want will be produced.
Why the Manual Method Doesn't Work for Big Files
Some Users try to sync files manually with IMAP; however, this doesn't work well for large files.
It works in theory, but in practice, it slows down and stops working. The procedure is not good for large amounts of data because it depends on how fast the internet is and how many emails the server can handle.
The manual method has a lot of problems:
- Very sluggish for data over 50GB
- There is a good probability that you will miss emails or attachments.
- Needs a constant internet connection
- No guarantee that all data will be sent
That's why users usually don't do manual conversion when moving a lot of data.
Best Way: Use a Professional OLM to PST Converter
The safest and best method of managing large files is by using professional software like GanTools OLM to PST Converter. Because this software is designed to manage very large amounts of data, it will not cause your computer to crash while using it.
Some advantages of using a professional application include:
- Ability to easily work with large files (greater than 50GB)
- Ability to maintain the structure of email messages and attachments
- Ability to split PST files into smaller parts
- Ability to filter which files to convert
Professional applications do not try to process everything at once; instead, they process data in a controlled and safe manner to prevent data loss and to avoid crashing your computer.
OLM to PST conversion could be done in a few simple steps.
- Install the Download OLM to PST Converter and run it on your computer.
- Click on Browse to select the OLM file you want to convert.
- Preview your data (emails, folders, and attachments are available for previewing.
- (Optional) Select the folders that you want to convert or apply filters if required.
- Choose "PST" as the output format and check the "Split PST" option if the file you are converting is large.
- Select the location on your computer where you want to save the PST file.
- Click the "Convert" button and wait for the conversion process to finish.
- Open the PST file in Outlook and verify that the data is correct.
Conclusion
So long as you follow the correct procedures, it is quite possible to successfully export a sizable 50GB+ OLM file to Outlook PST without problems. The key to accomplishing this task successfully is to not overwork your system and to plan your processing in advance.
Do not attempt to hurry up converting the data; rather, break this up into manageable pieces, set up your system for the conversion, and choose a software tool that you can trust.
Once you have done everything properly, your entire conversion will be successful, clean, safe, and quick; there will be no problems with crashes or other data loss.
