A large number of mailbox items per folder may impact the Exchange mailbox performance. You may notice a drop in performance while performing certain actions when there are a lot of mail items in an email folder, such as Inbox, Sent Items, etc. Further, a folder may fail to display correctly or take longer and lead to synchronization errors.

Microsoft recommends having up to 100,000 mail items per folder and up to 5,000 items per Calendar for PST files. For Exchange server mailbox and Office 365, the recommended limit is up to 1,000,000 mail items per folder to ensure the best performance and avoid performance issues.

Stellar Converter for EDB applies these recommended mailbox folder limits and automatically splits the large folders with the same name, based on date and time. It adds a suffix “<date-time>_earlier” to the folders.  

You don’t need to perform any additional action or select an option to split the mail items per folder. The software intelligently splits the folder when you save or export the converted mailboxes and items from an Exchange database (EDB) file to PST, Office 365, or live Exchange server.

How Stellar Converter for EDB Automatically Splits Mailbox Folder Based on Microsoft’s Recommended Limit?

PST File Stellar Converter for EDB splits and saves up to 90,000 mail items per folder while saving the mailbox in PST file format.
Live Exchange The software auto-splits and saves up to 900,000 mail items per folder while exporting the mailboxes or items to the live Exchange Server. 
Office 365 It saves up to 900,000 mail items per folder during Office 365 export under Microsoft’s recommended limits.

This helps you ensure optimal performance across all supported applications. To know more, refer to Mailbox Folder Limits recommended by Microsoft.