A fast and reliable tool developed by experts for professionals.
A quick internet search finds lots of tools that claim to import OST files into Outlook. Some are even free (or so they say) but which one is best? The best OST converter will recover your valuable mail without data loss. That’s exactly what Aid4Mail does. But what about the others?
Our research team identified at least 130 websites offering email conversion software (there are probably many more). Products from brands like SysTools, Advik, 4n6, Stellar, BitRecover, Kernel Data Recovery, Aryson, MailsDaddy, Shoviv. Almost all are from India and most are mediocre at best.
We tested dozens of these OST converter tools and the results were shockingly poor – missing emails, lost attachments, slow conversions, minimal documentation, deceptive marketing. SysTools OST to PST Converter failed to export anything at all, resulting in an empty PST file!
However, the worst offenders are products that initially appear to work but lose important data during conversion. Data that may not immediately be obvious like embedded content and email header fields (metadata).
So if those are the worst, let’s talk about the best.
Aid4Mail is a professional email converter that prides itself on converting without data loss. It is user-friendly software for Windows and supports a large number of mailbox formats and email accounts. These include OST, PST, Outlook 365, and Gmail.
Aid4Mail is used in a variety of contexts, ranging from small-scale, single-file imports to large-scale migrations and long-term criminal investigations. Customers include some of the biggest-name Fortune 500 companies, government agencies and legal professionals around the world.
A free Aid4Mail trial is available to download, and you will find step-by-step instructions (with screenshots) in our How to convert OST to PST tutorial. There are three editions of Aid4Mail, with licenses at various price points. One is an affordable two-week license for single-use conversions.
Aid4Mail doesn’t need Outlook to convert your mail and can process offline OST files directly. However, if Outlook is installed, Aid4Mail can hook into it to optimize performance (up to 4x faster) and access additional metadata. Either way, your OST files will be faithfully exported to PST with the folder structure intact.
Aid4Mail not only converts the content of an email message but also its metadata. This includes messages status flags: Unread, Read, Replied, etc. This information is often overlooked by competing products but can be crucial in an investigation or for maintaining archives for legal compliance.
An OST file no longer associated with its Outlook profile is an “orphan”. It can’t be opened by Microsoft Outlook. However, after conversion to PST with Aid4Mail, its mailbox data becomes accessible again. Not only to Outlook but to many other applications as well.
Unlike other products, when Aid4Mail encounters an error from a corrupt email, it doesn’t quit. Aid4Mail skips the problem item and continues with the rest of the mailbox, providing you with the most complete conversion possible.
Filter out unwanted mail, remove journaling envelopes, process incrementally, split and merge files, reconfigure folder structures, limit file sizes, inject additional metadata, customize with Python scripts, and more…
Set up multiple OST conversions in Aid4Mail to merge them into one PST file, for example, or to use different filters on each. In Aid4Mail Investigator and Enterprise, you can even run the conversions simultaneously and unattended. This leaves you free to work on something else while Aid4Mail is processing.
All the tools you need for preparing email evidence for legal proceedings, criminal investigations, litigation, compliance, auditing, or freedom of information (FOI) requests. Tools like recovering unpurged mail, advanced search and filter (including pre-acquisition), search lists, deduplication, file carving from disk images, Bates stamping, Python scripting, and more…
If you just want to convert an OST file to PST, then the affordable two-week Aid4Mail Converter license is perfect. If you regularly need to convert OST files, a one-year renewable license is more economical.
If you work in the field of digital forensics, consider Aid4Mail Investigator your tool of choice. It’s not just a great OST recovery tool, but can also be used to collect mail from a large number of mailbox formats and email service-providers. And it offers powerful tools to filter out unwanted emails and remove duplicates.
There’s lots more in Aid4Mail! The best way to discover its capabilities is to try it out. Download the free trial version now, there’s no time limit and no obligations.
For a detailed feature comparison between the three Aid4Mail editions, see the Aid4Mail 5 feature comparison table in PDF format.
We have been developing software since 1990. Our first email tool was launched in 1999 and Aid4Mail followed in 2005. Our experience in processing email data spans over two decades.
All core functionality in Aid4Mail is developed in-house. Key features are tightly integrated and optimized for speed. We are in full control of our code, including major components like email parsing and conversion, the filter engine and its search syntax, MAPI access to Outlook accounts, and even the IMAP protocol used to connect to services like Yahoo! Mail and AOL.
Important clients around the world rely on our software. These include US government and law enforcement agencies, top law firms, national libraries, prestigious universities, major banks, and international NGOs. Currently, half of Fortune 50 companies are Aid4Mail customers.
Aid4Mail is Swiss Made and meets the high-quality standards that Switzerland is famous for.
Where in the world were the products from? Of the 130 sites we investigated, here’s the breakdown:
Many of the companies making these products use deceptive marketing techniques. This is something we refuse to do as a company. For example, we found:
A Microsoft Outlook data file used by the Windows version of Outlook. It stores offline data from an Exchange server or Microsoft 365 (formerly Office 365), Outlook.com or IMAP account. OST files act as local storage to speed up mailbox access and reduce bandwidth usage. By default, they only contain messages that are less than a year old.
OST files in MS Outlook must be associated with an Outlook profile. A stand-alone OST file, no longer associated with its profile, is known as an orphan. It cannot be opened by Outlook so its data has become inaccessible.
A Microsoft Outlook data file used by the Windows version of Outlook to backup data. In older versions of Outlook, PST files were used for offline storage (as OST files are now) and are still used to store local POP account data.
PST files can be imported into Microsoft Outlook even when not associated with an Outlook account. They can also be imported into Outlook for Mac and are supported by a variety of other email-related applications.
There are 2 main reasons:
Please follow the step-by-step instructions in our How to convert OST to PST tutorial.
Yes! PST is the most common target format among Aid4Mail customers. PST files are used in:
Aid4Mail is a user-friendly Windows application that specializes in processing email: converting it from one format to another, searching it, and exporting it in useful ways.
There are a few manual methods to convert an OST file. Aid4Mail stands out from the crowd because its conversions are reliable and avoid data loss. Aid4Mail can recover mail from an OST, even if it’s damaged. And it can export to a whole range of file formats, email applications and services.
Yes! Aid4Mail can reliably convert large OST files and can even split them into multiple, smaller PST files. Aid4Mail can also process large batches of OST files. In the Investigator and Enterprise editions, Aid4Mail can even run them simultaneously and unattended!
Aid4Mail is installed with a very comprehensive, context-sensitive user guide. Just press the F1 key while using Aid4Mail to open it. Alternatively, you can download the PDF version.