You may across  Event ID 1022, Error 1245 in the application log of an Exchange 2007 mailbox server. The event can appear frequently and references a mailbox within the description, see the example below:

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Solution:

The 1245 error indicates that the mailbox referenced has exceeded the storage limit/quota configured on the mailbox database. To stop the errors occurring, clear down items in the referenced mailbox or re-configure your storage limits on the database:

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