User Mailbox Corruption When it Approaches Pre-defined Size Limit

Microsoft Exchange Server 2003 and 2000 enables the administrators to set size limits on user mailboxes in Exchange Organization. Setting the mailbox size limits helps administrator plan for the efficient backup and control the size of Exchange Server Database (EDB) file. However, if the mailbox exceeds size limit, it may stop accepting more data and get damaged. It leads to significant data loss situations. At this point, you can use the OST (Offline Storage Table) file of Microsoft Outlook to restore your mailbox. But, you need to first Convert OST File into PST (Personal Storage Table) file.
Under some circumstances, the user mailbox needs more storage space. As you receive more and more emails, the size of mailbox approaches its maximum size limit. At this point, you may face any of the below behaviors:
1)You get below error message, when you receive new emails:

"Your mailbox has exceeded one or more size limits set by your administrator.
Your mailbox size is "
2)When you try to send an email, Exchange Server gives you the below error:

"Task 'Microsoft Exchange Server - Sending' reported error (0x8004060C) : 'The message store has reached its maximum size. To reduce the amount of data in this message store, select some items that you no longer need, and permanently (SHIFT + DEL) delete them.'"
3)While receive emails, you get an error message stating:

"Mailbox Size Limit exceeded: This notification is to inform you that your mailbox size has reached the defined limit for Prohibiting Send.

Allotted Mailbox Size: 200 MB
Prohibit Send Limit: 90% of your allotted Mailbox size."
Cause
This behavior occurs when Exchange Server user mailbox exceeds maximum size limit, set by the Exchange administrator.
Resolution
In this case, you need to create a new profile and attach the Microsoft Outlook OST file to the mailbox to prevent data loss. However, the OST file cannot directly be attached to the mailbox. For this, you need to first Convert OST to PST manually, using third-party applications.
The OST PST conversion with specialized tools is quite easy as they have simple and interactive user interface. They use advanced algorithms to successful and absolute conversion. The applications convert your OST to PST safely as of their read-only conduct.
Stellar Phoenix Mailbox Exchange Desktop software effectively converts orphaned Outlook OST file into usable Outlook PST. The software works well with Microsoft Outlook 2007, 2003, 2002 (XP), and 2000. It converts all OST file objects, such as emails, notes, contacts, tasks, attachments, appointments, and more.