OST stands for the Offline Storage Table. This data file with .ost extension is entrusted in the vital task of ensuring offline access to the user. It also interacts with the Exchange to keep the mailbox folders up-to-date. In some cases, technical reasons prevent its proper synchronization. Sync issue in Outlook leads to severe consequences. This issue not only causes lost or duplicate email messages and calendar problems but can also lead to catastrophic data loss. This guide titled “How to Resolve Sync Issues in Outlook,” will shed light on the reasons as well as remedies of this sync issue. This post will also illustrate how to convert OST to PST free using Outlook. We will discuss how to fix corruption issues in .ost file using built-in features in the email client. In addition to this, we will also talk about an advanced OST to PST converter tool.
How to Verify that OST Syncing is Happening?
Follow the below procedure to ascertain if the syncing is proper and the mailbox is updated:
- Browse Outlook.
- Right-click on the folders.
- Then navigate to the Properties.
- In the Inbox Properties tab, click Synchronization.
- Now verify the Statics for this folder section.
- Statistics will tell the date and time of the sync update.
Consequences of Sync Issue in Outlook:
Improper synchronization can be catastrophic. It can lead to the following issues:
- Missing Emails: Regular sync issue can lead to missing or lost email messages. It means a barrier to crucial communication between peers or executives working on a project with tight deadlines.
- Data Loss: Let’s take a practical case. An employee is working Offline on some important tasks and the server is not available. If changes made locally are not properly synced once the connection is restored, then the offline data may be permanently lost due to corruption.
- Calendar Issues: In case the calendar entries fail to sync properly, an employee may missed important meetings or events.
Reasons and Remedies to Resolve Sync issue in Outlook:
After decoding consequences of Outlook sync issues, let’s discuss reasons as well as remedies to resolve this problem. Follow the below guide:
Reason 1: Poor Internet: An unstable or weak Internet can lead to sync issues. It is because the email client needs a consistent connection to synchronize data between the Exchange server and the .ost file. Due to a weak connection, uploading modifications done while working offline can’t be done.
Solution: Make sure that you are working on a stable, strong network. A high-speed Internet prevents sync issues as it stops late uploads and downloads of data.
Reason 2: Sync Not Happening: Many technical reasons can prevent synchronization of OST file with the Exchange Server. Factors like data file corruption, an oversized .ost file, etc. can hamper synchronization.
Solution: Manual Synchronization: Follow the below steps:
- Choose the targeted mailbox folder (that needs to be synchronized).
- Browse the Outlook ribbon.
- Now choose the Send/Receive.
- Choose Update Folder.
(The sync process message will appear in the lower-right part of the window).
Reason 3: An Oversized OST File: There is a default OST file size limit (50 GB in case of Microsoft 365 and Outlook 2010, 2013, 2016, 2019 versions). In case, this file surpasses this size limit, it can create sync issue in Outlook.
Solution: Compact the OST file: Follow the below steps for the same:
- Browse the Outlook.
- Navigate to the File.
- Go to Account Settings > Account Settings.
- Hit on the Data Files.
- Select the targeted .ost file.
- Press Settings.
- Then click Outlook Data File Settings.
- Press Compact Now.
Reason 4: A Damaged Outlook Data File (OST): One of the major reasons behind sync issue in Outlook is a corrupt .ost file. Any inconsistency in the data file can cause performance issues as well.
Solution: Rebuild Outlook Data File (OST): The step-by-step procedure is listed below:
- Exit Outlook.
- Locate the .ost file location. (It is C:\Users\AppData\Local\Microsoft\Outlook in 2019, 2016 and 2013 versions)
- Rename the .ost file for backup. Just add .bak. to the file name. (For example: rename yyy@aaa.com.ost, rename it to yyy@aaa.com.ost.bak.)
- Restart the Outlook email client. A new .ost file will be created. Investigate if the mailbox is synced properly.
It is always better to check for missing mailbox folders after recreating the Outlook data file (.ost). In case your findings suggest some data is missing then we can convert OST to PST free using Outlook’s Import/Export wizard. Follow the below instructions:
- Access Outlook with the same credentials with which the .ost file was created.
- Then go to Files> Open & Export> Import & Export.
- Now select ‘Export to a file’ action. Click ‘Next.’
- The user will come across a box ‘Export to a File’.
- In the file type, select the Outlook Data File (.pst) option. Click Next.
- Select targeted folders as well as sub-folders. Click Next.
- Provide folder path location for the new .pst file. Choose the option reading ‘Replace duplicates with items exported’ as well.
- After this click the ‘Finish’ tab.
What if the Manual Method Fails?
There is a high possibility that the above method may fail to transfer the entire mailbox data from OST files into PST. If the rebuilding method fails, a professional OST to PST converter tool can assist us. Such software features a friendly GUI. Additionally, these tools like Stellar Converter for OST maintain the hierarchy of folders. They can quickly convert all mailbox content in a few steps. Such converters can also extract folders from orphaned or inaccessible OST files.
Conclusion
In the above guide titled “How to Resolve Sync Issues in Outlook,” we have explored possible reasons behind synchronization error as well as their remedies. The post also sheds light on consequences of sync issues that range from missing/ lost emails and data loss to calendar issues. We have also discussed if the Outlook data file (.ost) is damaged then we can rebuild it by taking its backup. It is a possibility that even after recreation, the user discovers some missing mailbox folders. Such a situation is worrisome. We can overcome this scenario using any specialized OST to PST converter tool. Such tools are smart enough to scratch folders even from inaccessible or orphaned data files (.ost). Stellar Converter for OST is one of such tools that is recommended by experts. It is fast and easy-to-use. This tool can convert even an unreadable data file (.ost) to a .pst format.