Split and Merge Outlook PST Files in C#

PST (Personal Storage Table) files are used by Microsoft Outlook to store email messages, calendar events, contacts, and other items. Over time, as emails and other data accumulate, they can become very large, which can lead to performance issues, difficulty in management, and higher risk of corruption. To address these challenges, splitting larger data into smaller, more manageable chunks is a common practice. Conversely, when consolidating data from multiple sources, merging becomes necessary.

Splitting helps reduce size, improve performance, and organize content based on specific criteria, such as by date, folder, or other attributes. Merging is useful for users who want to consolidate multiple storages into a single one, often for archival purposes or when combining mailboxes after migration.

By performing splitting and merging operations, users can enhance the usability and maintainability of their email storage. This guide explains how to achieve these tasks programmatically using .NET, focusing on key functionalities to control file sizes, merge multiple PSTs, and handle events that occur during these processes.

C# API to Handle PST Files

For handling PST files, we will use Aspose.Email for .NET, a versatile email management library that offers advanced functionality for email-related tasks. This API enables developers to work with emails, calendars, contacts, and more, making it a powerful tool for applications requiring robust email processing. The Aspose.Email for .NET API excels in managing large PST files by providing the ability to split and merge them. These capabilities make it an ideal solution for developing automated processes that handle PST file management efficiently, ensuring smooth data handling within .NET applications.

To leverage the power of the library, simply install it using the NuGet Package Manager and integrate it into your project:

  • Open your project in Visual Studio.
  • Navigate to Tools > NuGet Package Manager > Manage NuGet Packages for Solution.
  • Search for Aspose.Email.
  • Select the package and click Install.

Alternatively, you can use the Package Manager Console and type in the following command:

Install-Package Aspose.Email

You can also download the latest version of the API directly from the Aspose website.

Once the library is installed, start coding!

Merge PST Files

Aspose.Email allows you to merge multiple PSTs, thus consolidating email data into a single file and simplifying data management. This can be especially helpful when handling backups or archives scattered across different sources or when combining data from multiple accounts. The API provides a MergeWith method which allows you to merge PST files seamlessly.

The following steps outline how to merge two or more PST files programmatically:

  1. First, load the primary PST where you want to consolidate data.
  2. Specify an array of paths to the source PSTs that need to be merged into the target one.
  3. Use the MergeWith method on the target PST, passing the array of source paths. This will merge the contents, preserving folder structures and items such as emails, contacts, and calendar entries.
  4. Attach event handlers to monitor the merging process. Events like StorageProcessing and StorageProcessed provide updates on the current PST being processed and when it has been successfully merged.

Code Example:

Split PST File into Smaller Parts

When managing large PSTs, splitting them into smaller parts can help improve performance and handle file size limitations more effectively. The process involves dividing a large PST into chunks of a specified size. The following steps outline the process of splitting a PST file into smaller parts using Aspose.Email API:

  1. Use the PersonalStorage.FromFile method to load the PST file from the specified file path.
  2. Define the maximum size of each split part in bytes.
  3. Set a prefix for each split file’s name and specify the directory where the split files will be saved.
  4. Attach event handlers to monitor the splitting process.
  5. Use the SplitInto method to split the PST based on the chunk size. The method will create multiple smaller PSTs in the destination directory.

Here’s a code example that demonstrates how to split a PST file into smaller parts:

Splitting by Criteria

Splitting PST files based on specific criteria can help manage and organize large amounts of data more effectively. This approach allows you to break down a PST file into smaller, more manageable parts according to defined rules or conditions. For instance, you might want to split a PST based on the date range of emails, sender addresses, or message importance. In this section, we’ll explore how to split a PST using criteria.

To split by criteria with Aspose.Email API, you’ll need to define MailQuery objects that represent your filtering criteria. These criteria are used to determine how the PST file will be devided into parts. The SplitInto method of the PersonalStorage class allows you to specify these criteria and generate the corresponding parts.

  1. Load a PST File using the PersonalStorage.FromFile method.
  2. Define Criteria. Create MailQuery objects to specify the criteria for splitting. In this example, we will define two queries: one based on the sent date and another based on the sender’s email address.
  3. Split the PST: The pst.SplitInto(queries, filePrefix, outputPath) method devides the PST into parts based on the defined criteria and saves them with the specified prefix in the output folder.

Here’s an example demonstrating how to split a PST file based on criteria:

Conclusion

In this article, we’ve explored how to:

  • Combine two or more PST files into a single file, making it easier to manage and consolidate email data.
  • Divide a large PST file into smaller parts based on size or criteria, which helps in organizing and distributing data effectively.

Additionally, we’ve seen how to use event handlers to monitor the progress of these operations, providing real-time feedback and control over the process.

To perform the above stated tasks, we used the C# API of the advanced and robust Aspose.Email for .NET library which also provides a number of free resources:

  • a comprehensive documentation,
  • an extensive API reference,
  • a variety of free online tools and apps to enhance the development process,
  • free support forum for community assistance and insights,
  • the blog to stay updated with the latest tips and tutorials.

These resources are invaluable for maximizing the potential of the library in your projects.

See Also