Once the mailbox size is increased, it should probably fix the error. One way to resolve the error is to ask the Exchange admin to increase the mailbox size limit. How to Resolve OST Has Reached the Maximum Size Error?
Similarly, you stop receiving any new mails and face several other issues until you resolve the error. In such cases, the changes you make are not saved or emails you send are not sent. The error may also appear when the OST file size reaches the configured mailbox size limit on the Exchange server. When the size of OST increases and reaches its threshold or file size limit configured on the system, the error OST file has reached the maximum size may appear.
The file is stored on the system locally and syncs the changes made to Outlook with the user mailbox on the server. OST or Offline Storage Table is a replica of the user mailbox on the Exchange server. In this guide, we have shared a few fixes and solutions that can help you resolve the OST file size issue in Windows Outlook. Summary: OST file has reached the maximum size is an error message that appears when the size of OST reaches its configured file size or threshold limit.
