You can convert your EML files into a single PST by using a dedicated tool like MailsDaddy EML to PST Converter software . The tool supports batch migration and allows users to view EML file email content with attachments. It preserves email formatting, attachments, metadata, and folder structure during the conversion process. Migrate emails from Windows Live Mail, Thunderbird, and other EML-supported email clients to Microsoft Outlook. It works smoothly with all editions of Microsoft Outlook and Windows operating systems.

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Yes, and it's actually one of the more common things people need to do when switching email clients or migrating from Thunderbird, Windows Live Mail, or just about any client that saves mail in .eml format. The short answer is: you can batch convert all your EML files into a single PST file, and it's not as complicated as it sounds.
The reason people hit a wall here is that EML and PST are fundamentally different formats. EML stores one email per file — open it and it's just that message. PST is a container format used by Outlook, meaning it holds folders, emails, attachments, and metadata all in one place. So converting isn't just a file rename; something actually has to map all those individual .eml files into a proper folder structure inside a .pst container.
If you're dealing with a handful of messages, you could drag them into Outlook manually. But if you've got hundreds or thousands of EML files — which is the usual scenario after an export — you need something that handles the batch process cleanly without scrambling the folder hierarchy or dropping attachments.
That's where a dedicated converter makes sense. The Macsonik EML Converter  handles exactly this: you point it at a folder of EML files, and it converts the entire batch into a single PST file that Outlook can open directly. It preserves folder structure, keeps attachments intact, and doesn't require you to have Outlook running during conversion — which matters if you're doing this on a machine that doesn't even have Outlook installed yet.
A few things worth keeping in mind before you start: make sure your EML files are organized into folders the way you want them to appear inside the PST, because the tool will mirror that structure. Also, if you're migrating to a corporate Exchange account, confirm with your IT team whether they want a PST import or prefer you use a different onboarding path — sometimes the answer changes how you want to structure the output.
But for most personal migrations and archiving scenarios, batch EML to PST conversion is straightforward once you have the right tool. Trying to do it manually at scale is where people lose an afternoon they're not getting back.