By default Microsoft Outlook is configured with OST or PST file size restrictions. If your data file will grow up to the critical value, you will be notified first and then Outlook will block the write operations. Then you have several possible ways to continue work with Outlook:

1. you may remove the old emails and compact the PST file to reduce its size and make more space available;

The maximum default PST and OST files size per Outlook version:
  • Outlook 2016 - 50 GB
  • Outlook 2013 - 50 GB
  • Outlook 2010 - 50 GB
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