Hello, I receive the following error repeatedly from my Microsoft Operation Manager Server: Severity: Critical Error Status: New Source: Exchange MOM Name: Outlook Mobile Access logon failure: Unexpected errors. Description: Error during synthetic Outlook Mobile Access logon. To determine the current state of this problem, look at the events associated with this alert and find the most recent event. The initial event reported that: Cannot measure OMA availability for the following URL: 0x80131502(-2146233086) Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index This event was generated by the script: "Exchange 2003 - OMA logon verification" I looked at the most recent events and they simply repeat the same INDEX out of range message. I looked at http://www.microsoft.com/technet/prodtechnol/exchange/2003/empconfig.mspx but none of those suggestions seemed to apply to this error. Any help appreciated. Bill