Large Outlook PST files are a common pain point for anyone managing heavy email workflows. When an Outlook PST file gets too large, sending it as an email attachment or simply keeping Outlook running smoothly becomes a major headache. Large file sizes can lead to slow performance, frequent freezing, Outlook crashes, and even severe file corruption.If you are struggling with a PST file too large for email attachment errors or need to share email data without hitting strict file size limits, there are reliable ways to fix this. In this guide, we will explore why PST file size limits matter, how to reduce or split PST files manually within Microsoft Outlook, and how to use a dedicated third-party utility to streamline the entire process.Why Large PST Files Cause Problems in OutlookMicrosoft Outlook uses PST (Personal Storage Table) files to store emails, contacts, calendar events, tasks, and attachments locally. While modern versions of Outlook support large PST file limits (up to 50 GB by default), letting your PST file get close to or exceed these limits creates several issues:<ul><li>Email Attachment Limits: Most email providers (like Gmail, <a target="_blank" rel="noopener noreferrer nofollow" href="http://Outlook.com">Outlook.com</a>, or enterprise Exchange servers) restrict attachment sizes between 20 MB and 25 MB. Sending a complete PST file via email is practically impossible.</li><li>Outlook Performance Lag: As a PST file grows, Outlook takes much longer to search for messages, open folders, and process incoming or outgoing mail.</li><li>Increased Risk of File Corruption: The larger a PST file gets, the more susceptible it becomes to corruption during unexpected system shutdowns or software crashes.</li><li>Backup and Storage Hassles: Backing up or moving a single massive file across cloud drives or local storage media is slow and prone to network timeouts.</li></ul>Method 1: Manual Solutions in Microsoft OutlookMicrosoft Outlook provides built-in tools to manage, reduce, and archive your data. While these manual options do not directly "cut" a single PST file into multiple smaller pieces automatically, they allow you to split data into separate PST files by date or archive old items.Solution A: Use the AutoArchive FeatureOutlook’s archive feature moves older emails and items from your primary PST file into a separate archive PST file, reducing the overall size of your active working file.Steps to Archive Emails in Outlook:<ol><li>Open Microsoft Outlook.</li><li>Click on the File tab in the top-left corner.</li><li>Select Info, then click on Tools (or Cleanup Tools) and choose Clean Up Old Items... (or Archive...).</li><li>Select the Archive this folder and all subfolders option.</li><li>Choose the specific folder you want to archive (such as Inbox or Sent Items).</li><li>In the Archive items older than: field, select a cutoff date.</li><li>Click Browse to specify the save location and name for your new archive PST file.</li><li>Click OK to start the process.</li></ol>Note: Archiving creates a new PST file containing your older data, leaving your main PST file significantly smaller.Solution B: Manually Move Emails to a New PST FileIf you want complete control over which emails go into which PST file (for example, organizing by project, client, or year), you can create a new PST file manually and drag items into it.Steps to Create and Split Data Manually:<ol><li>In Outlook, go to the Home tab.</li><li>Click on New Items &gt; More Items &gt; Outlook Data File.</li><li>Choose a folder location, give your new PST file a name (e.g., Emails_2023.pst), and click OK.</li><li>You will now see this new PST file listed in the left-hand navigation pane of Outlook.</li><li>Go to your primary PST file, select the emails or folders you want to move, and drag and drop (or right-click and choose Move) them into the new PST file folders.</li><li>Once transferred, right-click the top folder of the newly created PST file and select Close to detach it from Outlook.</li></ol>Solution C: Compact the PST FileAfter deleting or moving large amounts of data out of your main PST file, Outlook does not automatically shrink the file on your hard drive. You must manually compact it to claim back unused storage space.Steps to Compact a PST File:<ol><li>In Outlook, go to File &gt; Account Settings &gt; Account Settings.</li><li>Switch to the Data Files tab.</li><li>Select your PST file and click Settings.</li><li>In the dialog box that appears, click the Compact Now button.</li><li>Click OK when finished.</li></ol>Limitations of Manual MethodsWhile manual techniques cost nothing, they come with notable drawbacks:<ul><li>Time-Consuming: Moving thousands of emails manually or setting up multiple archives takes considerable time.</li><li>No Automated Size-Based Splitting: Outlook cannot automatically divide a 20 GB file into four equal 5 GB chunks.</li><li>Risk of Human Error: Moving items manually increases the risk of accidentally missing critical emails or folders.</li><li>Potential System Freezes: Dragging massive quantities of items at once can cause Outlook to freeze or crash mid-transfer.</li></ul>Method 2: Third-Party Automated Tool SolutionWhen manual methods prove too slow or complex, dedicated third-party utilities offer an automated, hassle-free alternative. A specialized utility designed specifically for this task is the GainTools Split PST Software, which allows you to divide oversized PST files into manageable pieces seamlessly without risking data loss.Advantages of Using a Specialized Split Utility<ol><li>Split by Specific Criteria: You can split oversized PST files by size (e.g., 1 GB, 2 GB, 5 GB chunks), by year, by folder, or by date range.</li><li>Maintains Folder Hierarchy: Keeps all original subfolders, read/unread statuses, attachments, and metadata intact.</li><li>No Outlook Dependency: Many advanced utilities can process PST files independently without requiring Outlook to be running.</li><li>Prevents File Corruption: Splitting massive files into smaller units reduces system load and keeps your Outlook data healthy.</li></ol>General Steps to Use an Automated PST Split Tool:<ol><li>Download and Install: Launch the software on your Windows computer.</li></ol><ol><li>Add PST File: Browse and select the large PST file you want to break down.</li><li>Choose Split Option: Select your preferred criteria (such as splitting by file size or date).</li><li>Set Output Destination: Pick the folder where you want the new, smaller PST files saved.</li><li>Start Splitting: Click the process/convert button to create smaller, lightweight PST files automatically.</li></ol>FeatureComparison: Manual Outlook Methods vs. Automated Tool<ul><li>Feature Manual Outlook Methods Automated PST Split Tool</li><li>Effort Required High (manual folder creation and item moving) Low (automated single-click processing)</li><li>Size-Based Splitting Not supported directly Fully supported (custom MB/GB limits)</li><li>Data Safety Risk of accidental deletion during manual drag-and-drop High precision; original file remains</li><li>untouched</li></ul>Speed Slow for large data volumes Very fast processingOutlook Requirement MS Outlook must be installed and configured Works independently of OutlookBest Practices for Managing Outlook PST FilesTo prevent your PST files from causing attachment or performance problems in the future, follow these best practices:<ul><li>Regular Maintenance: Run AutoArchive every few months to keep your primary PST file lightweight.</li><li>Avoid Storing Large Attachments in PSTs: Save heavy attachments to cloud storage (Google Drive, OneDrive, Dropbox) or local drives and share download links instead of attaching large files directly to emails.</li><li>Keep Backup Copies: Always create a duplicate copy of your primary PST file before performing manual cleanup operations or running split utilities.</li><li>Monitor Storage Limits: Check your PST file size periodically in File Explorer to ensure it stays well below the 20–30 GB mark for optimal performance.</li></ul>Frequently Asked Questions (FAQs)Q1. What is the maximum email attachment limit in Microsoft Outlook?Most email service providers, including Microsoft Outlook and Gmail, limit email attachments to 20 MB or 25 MB per email. For larger files, cloud links or file-splitting tools are recommended.Q2. Can I compress a PST file without deleting emails?Yes, you can use Outlook's built-in Compact Now feature. It removes unallocated white space left behind after archiving or deleting items, reducing the PST file size without deleting any existing data.Q3. Why is my PST file size not reducing after deleting emails?When you delete emails from Outlook, the space they occupied is marked as empty space within the PST file. You must run the Compact Now option to reclaim that space on your hard drive.Q4. Is it safe to split large PST files?Yes, as long as you maintain a backup copy of your original file before initiating any manual or automated splitting process.ConclusionHandling oversized Outlook files does not have to be difficult. Manual approaches like AutoArchiving, creating secondary PST files, and compacting data offer effective built-in remedies within Microsoft Outlook. However, for a quick, automated, and precise way to break large PST files down by size or date without manual effort, utilizing a specialized solution like the GainTools Split PST Software ensures your email management remains effortless and secure.Visit Website: <a target="_blank" rel="noopener noreferrer nofollow" href="https://www.gaintools.com/split-pst/">https://www.gaintools.com/split-pst/</a>

PST File Too Large for Email Attachment? Here Are Better Solutions

Microsoft Outlook stores your emails, contacts, calendars, and tasks in files known as PST files. Many people password-protect these files to protect this personal or corporate information. But if you forget or lose the password you will not be able to access your emails and archives.If you have been locked out of your PST files, this straightforward instruction will teach you how to unlock them manually and with the help of an automatic program, and get access to them fast.Why Are Outlook PST Files Locked?PST files are password-secured; nevertheless, there are a few typical reasons why you can lose access to them:Lost Passwords: Strong passwords contain complicated characters and numbers, yet they might be simple to forget.Changing Jobs: When an employee quits a firm, they may leave password-protected archive files without leaving the password.File Corruption: Sudden computer shutdowns might result in file issues, causing Outlook to suddenly ask for a password.Managing many files: If you have several old PST files preserved over many years, it is hard to remember every password.<h2>Method 1: Manually Remove or Reset Outlook PST Passwords</h2>If you know the current password or wish to attempt basic features inside Outlook, manual techniques are ideal.Option A: Remove Password in MS Outlook(Note: you need to know the current password for this option.)If you know your current password and wish to clear it so that Outlook will no longer prompt you for it, do the following:Open Microsoft Outlook.Click File &gt; Account Settings &gt; Account Settings.Go to the Data Files TabChoose your locked PST file from the list and click Settings.Click Change Password button.In the Old Password box, type your current password.Leave the New Password and Verify Password fields empty.Click OK to save adjustments.Option B: Using an Old Command Tool (pst19upg)(Note: This only works on extremely old PST files written with Outlook 2002 or earlier versions.)Microsoft used to have a little utility called pst19upg.exe that would update older files and delete passwords in the process.Exit Microsoft Outlook fully and copy your PST file to a secure place for backup.Use the built-in repair tool (scanpst.exe) to rectify tiny mistakes in the file.Open your computer's Command Prompt.Run the command: pst19upg.exe -x outlook.pstThis will produce a temporary .psx file.Enter the second command: pst19upg.exe -i filename.psxThis will create a fresh PST file without a password. This may now be opened in Outlook.Limitations of human methods:Requires Current Password: If you totally forget your password, Outlook will not be able to erase it.One file at a time: You can't unlock more than one file at a time, which is quite time-consuming.Not Compatible with Newer Outlook Versions: The old command tools cannot function with the PST files of Outlook 2007, 2010, 2013, 2016, 2019, and Office 365.File destruction risk: Command prompt errors might destroy your file.<h3>Method 2: Instant PST Files Unlock using Automated Software</h3>If you forget your password or you need to unlock numerous files at one time, the manual instructions will not work. Automated programs allow you to unlock PST files without the original password.With the help of a professional application like GainTools PST Password Recovery Software, this procedure becomes straightforward and quick, as it runs smoothly on all new and old Outlook file formats without losing any data.Key Advantages of Utilizing an Automated Tool:Supports opening multiple files. You may open and work with several PST files at the same time.Does not require Microsoft Outlook to be installed and configured on your machine.Removes Complex Passwords: Unlocks files with long complex passwords instantly.Secures Your Data – Removes password protection without damaging your emails, attachments, ts and files.Steps to Recover Password of Multiple PST FilesLaunch the recovery program on your PC.Click Browse or Add Folder to choose one or more PST files.Choose Remove Password or Reset Password.Click the Process button and get your files quickly and delete the passwords.ConclusionIf you know your password, you may deactivate it quickly with the Outlook settings. But if you have forgotten your password or have several locked PST files, then the quickest and safest approach to recover your data is to use a professional software application.<blockquote>Visit Website: <a target="_blank" rel="noopener noreferrer nofollow" href="https://www.gaintools.com/pst/password/">https://www.gaintools.com/pst/password/</a></blockquote>

A Complete Guide to Recover Forgotten Passwords from Multiple Outlook PST Files

If you’ve been using Microsoft Outlook for years, chances are your system has collected a lot of Personal Storage Table (PST) files. Old archives, data from previous projects or different mailboxes created over time might lead to an administrative nightmare in a hurry, when you need to manage many PST files. It's a hassle to search for a given message in 5 or 6 unique files. It also affects your system speed tremendously.The good news is that it is very possible to merge your email data. In this post, we will go over the reasons why you need to combine your files, show you the native manual technique using MS Outlook, and present you with a faster and safer third-party solution.When do you need to combine several PST files?But before we go into the solutions, let’s first understand why managing fragmented Outlook files is an unproductive practice.Performance Lag: MS Outlook has a hard time managing many massive data files at a time. Opening and indexing many PST files might lead to excessive CPU load and delay in running the software.Complex Searching: If emails are kept in different archives and folders, it may take time to search through files one by one to find an important piece of correspondence.Storage and Backup Overhead. Securing 10 little PST files is far more chaotic than securing one well-structured master file. It has the potential to lose or delete crucial records.Chance of Corruption: A larger, more fragmented Outlook Profile indicates a higher chance of PST corruption from an unexpected crash of the application or system shutdown.Consolidating your data into one repository eliminates these problems and makes your digital workspace much more efficient.<h2>Method 1: Using MS Outlook (Manual Native Method)</h2>If you don’t want to install additional apps and want a built-in solution, there is a manual approach in Microsoft Outlook. The way around this is to create a new blank PST file and then use the Import/Export wizard to import your current PST archives into the new PST file.1. Create a new blank PST<ul><li>Open Microsoft Outlook on your PC.</li></ul><ul><li>Click New Items &gt; More Items &gt; Outlook Data File on the top ribbon.</li></ul><ul><li>Select a proper location on your local drive to save this new file, name it clearly (e.g., MasterArchive.pst), and click OK.</li></ul>Now, the new empty PST file will be seen in the left navigation pane of your Outlook window.Step 2: Importing Existing PST Files to New FileFile &gt; Open/Export &gt; Import ExportIn the Import and Export Wizard dialog box, choose Import from another program or file, and then click Next.Select Outlook Data File (.pst) as the kind of file and then press Next.Click Browse to choose the first PST file that you want to integrate.Go to Settings, pick "Do not import duplicates (recommended to keep your data clean)" and click Next.3. Select the folder in that PST file that you want to import. Be sure you check the box for Include subfolders, then select the radio option that says Import stuff into the same folder in:, and then select your newly created MasterArchive.pst file from the drop-down menu.Click Finish.Disadvantages of the manual procedureThe manual technique is free, but has some severe downsides:Time Consuming: If you have many large PST files, then you will need to manually perform this multi-step import procedure for every file.Risk of Data Loss or Error by Humans. A single misclick in folder mapping might result in data being erased or subfolders vanishing.Advanced filtering is missing: There's no straightforward way to relate specified items (e.g., calendars or certain date ranges) without long pre-filtering.<h3>Method 2: The Right Way – Third-Party Software Solution</h3>Importing large volumes of important business or personal email history manually may be time-consuming and dangerous. This is where a dedicated third-party utility comes in.It’s meant to circumvent the dull restrictions of manual sorting. GainTools Merge PST Software helps you simply and safely combine two or more PST files into one consolidated file.Key Features of Professional PST Merger ToolsBulk Merging Feature: Merge unlimited Unicode or ANSI PST files into a single healthy PST file without any file size limitation.Selective Folder Organization: Enables users to see mailbox folders before merging and modify the arrangement of files using simple controls.No reliance on MS Outlook: The application can complete the merging operation effectively even if MS Outlook is not installed on your PC.Maintains Data Integrity: It retains the folder structure and formatting of all mailbox elements such as emails, contacts, calendars, tasks, notes, and journals.Duplicate Item Management: Comes with built-in capabilities to handle overlapping or redundant emails so you don’t have a bloated final master file.User Interface: It is a basic yet clear wizard design. Easy to use. So, you don’t need any big technical skills to use it.How to use the automatic tool: instructionsThe professional utility takes minutes to run. To archive your emails in one place, follow these simple steps:Download and Run: Download the tool from the official website, install it on your Windows operating system, and run the application.Add PST Files: On the software interface, click Add File or Add Folder to browse and upload the target PST files you wish to merge.Review and Rearrange: After uploading the files, you may preview the information. Alternatively, you may configure the processing order using the administrative features of the application.Browse option: Click this option to select where the combined PST file will be saved on your local drive.Merge Now: Click on the Merge Now (or Start Merging) button. The application will scan the data, and in seconds you will get a clean PST file.Conclusion:Manage your email archive. Nothing makes your digital office seem cramped like a dirty inbox. Microsoft Outlook’s built-in import tool is good enough for casual users who simply need to import one or two small files, but it doesn’t scale well for large multi-file databases.So, if you want to combine your archives easily, swiftly, and securely, without any possibility of data loss, you should utilize the automated PST merging program. This is a professional-level solution. Combining all your emails into one strong file may dramatically improve search times, reduce system resource usage, and provide you with total peace of mind regarding your digital records.Visit Website: <a target="_blank" rel="noopener noreferrer nofollow" href="https://www.gaintools.com/merge-pst/">https://www.gaintools.com/merge-pst/</a>

Daniel White

Publication history

PST File Too Large for Email Attachment? Here Are Better Solutions

A Complete Guide to Recover Forgotten Passwords from Multiple Outlook PST Files

How to Merge Multiple PST Files into One for Better Email Management