So I have Exchange 2003 SP2 and SBS 2003 SP1. I have been getting Event ID 9667 for several days and have done extensive research on the problem.But in referring to http://technet.microsoft.com/en-us/library/bb851495.aspxand other articles, I have found that they always reference the Source of the Event as msgidNamedProsQuotaError. My Event ID 9667always references the source as MSExchangeIS.My question is are these the same errors. Everything else matches up, but I am worried about increasing my quotas if these are different events.Thank you.

did you get a chance to look into this post http://social.technet.microsoft.com/Forums/en-US/exchangesvradmin/thread/8c19ad86-1f24-499d-8933-dd99b322dac5Raj

Hi, Please follow the steps in 820379 entirely to set the quota values for each of the objects and dismount/remount the store.820379 How to configure quota settings for named properties and for replica identifiers in Exchange Server 2003 and in Exchange Server 2007http://support.microsoft.com/default.aspx?scid=kb;EN-US;820379 Understanding the Impact of Named Property and Replica Identifier Limits on Exchange Databaseshttp://technet.microsoft.com/en-us/library/bb851492.aspx To avoid this issue in the future, please do not allow a particular mailbox store database to grow more than 50 - 60 GB. For more information, please refer to the following article:Database and log files stored on same disk volumehttp://technet.microsoft.com/en-us/library/aa996891.aspx Regards, Xiu