Other than doing a set mailbox after the mailbox is created. Is there a way the default mailboxregional settings and be changed and the default calendar processing changed so that when a new mailbox is created it automatically inherits these> For example default bookingindays window is 180, i need this at 450. Regional settings to en-AU and so on We have issues in our automated process were sometimes these commands don't run properly using a set-mailbox command when we have a mass account creation happen. I want to somehow set these at mailbox creation time and NOT use the set-mailbox command as that relies on the mailbox being created and available which sometimes it isnt.

this is the corresponding error in event viewer Microsoft.Exchange.Data.Storage.MailboxUnavailableException: Cannot open mailbox /o=UOFAPRD/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Configuration/cn=Servers/cn=mailserver/cn=Microsoft System Attendant. ---> Microsoft.Mapi.MapiExceptionUnknownUser: MapiExceptionUnknownUser: Unable to open message store. (hr=0x80004005,

Hi, Based on my research, mailbox deeafult value is predefined, we are not able to change it. I'd suggest you trouble why Set-mailbox failed. Could you provide the entire error event and the response message in CMS box? IT would help my research. Thanks. Fiona Liao TechNet Community Support

Set-CalendarProcessing {Identity=a1630315, DomainController=blackbird.ad.adelaide.edu.au, ErrorAction=Stop, AllowConflicts=True, BookingWindowInDays=450, EnforceSchedulingHorizon=False} ad.adelaide.edu.au/Core Services/Service Accounts/Service Account - DirXML ConsoleHost-Local 2688 5 00:00:00.0156251 View Entire Forest: 'True', Microsoft.Exchange.Data.Storage.MailboxUnavailableException: Cannot open mailbox /o=UOFAPRD/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Configuration/cn=Servers/cn=MAILMB02/cn=Microsoft System Attendant. ---> Microsoft.Mapi.MapiExceptionUnknownUser: MapiExceptionUnknownUser: Unable to open message store. (hr=0x80004005, ec=1003) Diagnostic context: Lid: 55847 EMSMDBPOOL.EcPoolSessionDoRpc called [length=230] Lid: 43559 EMSMDBPOOL.EcPoolSessionDoRpc returned [ec=0x0][length=248][latency=0] Lid: 23226 --- ROP Parse Start --- Lid: 27962 ROP: ropLogon [254] Lid: 17082 ROP Error: 0x3EB Lid: 26937 Lid: 21921 StoreEc: 0x3EB Lid: 27962 ROP: ropExtendedError [250] Lid: 1494 ---- Remote Context Beg ---- Lid: 26426 ROP: ropLogon [254] Lid: 25805 Error: 0x0 Lid: 11752 StoreEc: 0x8004010F Lid: 19149 Error: 0x0 Lid: 25805 Error: 0x0 Lid: 11752 StoreEc: 0x8004010F Lid: 22787 Error: 0x0 Lid: 13800 StoreEc: 0x8004010F Lid: 9448 StoreEc: 0x8004010F Lid: 16454 Lid: 16966 StoreEc: 0x8004010F Lid: 31433 StoreEc: 0x8004010F Lid: 8620 StoreEc: 0x3EB Lid: 1750 ---- Remote Context End ---- Lid: 26849 Lid: 21817 ROP Failure: 0x3EB Lid: 26297 Lid: 16585 StoreEc: 0x3EB Lid: 32441 Lid: 1706 StoreEc: 0x3EB Lid: 24761 Lid: 20665 StoreEc: 0x3EB Lid: 25785 Lid: 29881 StoreEc: 0x3EB at Microsoft.Mapi.MapiExceptionHelper.ThrowIfError(String message, Int32 hresult, SafeExInterfaceHandle iUnknown, Exception innerException) at Microsoft.Mapi.ExRpcConnection.OpenMsgStore(OpenStoreFlag storeFlags, String mailboxDn, Guid mailboxGuid, Guid mdbGuid, MapiStore msgStorePrivate, String& correctServerDn, ClientIdentityInfo clientIdentityAs, String userDnAs, String applicationId, CultureInfo cultureInfo) at Microsoft.Mapi.MapiStore.OpenMapiStore(String serverDn, String userDn, String mailboxDn, Guid guidMailbox, Guid guidMdb, String userName, String domainName, String password, String httpProxyServerName, ConnectFlag connectFlags, OpenStoreFlag storeFlags, CultureInfo cultureInfo, Boolean wantRedirect, String& correctServerDN, ClientIdentityInfo clientIdentity, String applicationId, Client xropClient, Boolean wantWebServices, Byte[] clientSessionInfo, TimeSpan connectionTimeout) at Microsoft.Mapi.MapiStore.OpenMailbox(String serverDn, String userDn, String mailboxDn, String userName, String domainName, String password, ConnectFlag connectFlags, OpenStoreFlag storeFlags, CultureInfo cultureInfo, WindowsIdentity windowsIdentity, String applicationId) at Microsoft.Exchange.Data.Storage.MailboxSession.ForceOpen(MapiStore linkedStore) --- End of inner exception stack trace --- at Microsoft.Exchange.Data.Storage.MailboxSession.ForceOpen(MapiStore linkedStore) at Microsoft.Exchange.Data.Storage.MailboxSession.Initialize(MapiStore linkedStore, LogonType logonType, ExchangePrincipal owner, DelegateLogonUser delegateUser, Object identity, OpenMailboxSessionFlags flags, GenericIdentity auxiliaryIdentity) at Microsoft.Exchange.Data.Storage.MailboxSession.<>c__DisplayClass12.<CreateMailboxSession>b__10(MailboxSession mailboxSession) at Microsoft.Exchange.Data.Storage.MailboxSession.InternalCreateMailboxSession(LogonType logonType, ExchangePrincipal owner, CultureInfo cultureInfo, String clientInfoString, IAccountingObject budget, Action`1 initializeMailboxSession, InitializeMailboxSessionFailure initializeMailboxSessionFailure) at Microsoft.Exchange.Data.Storage.MailboxSession.CreateMailboxSession(LogonType logonType, ExchangePrincipal owner, DelegateLogonUser delegateUser, Object identity, OpenMailboxSessionFlags flags, CultureInfo cultureInfo, String clientInfoString, PropertyDefinition[] mailboxProperties, IList`1 foldersToInit, GenericIdentity auxiliaryIdentity, IAccountingObject budget) at Microsoft.Exchange.Data.Storage.MailboxSession.ConfigurableOpen(ExchangePrincipal mailbox, MailboxAccessInfo accessInfo, CultureInfo cultureInfo, String clientInfoString, LogonType logonType, PropertyDefinition[] mailboxProperties, InitializationFlags initFlags, IList`1 foldersToInit, IAccountingObject budget) at Microsoft.Exchange.Data.Storage.MailboxSession.OpenAsAdmin(ExchangePrincipal mailboxOwner, MailboxAccessInfo accessInfo, LogonType logonType, CultureInfo cultureInfo, String clientInfoString, Boolean useLocalRpc, Boolean ignoreHomeMdb, Boolean recoveryDatabase) at Microsoft.Exchange.Data.Storage.MailboxSession.OpenAsAdmin(ExchangePrincipal mailboxOwner, CultureInfo cultureInfo, String clientInfoString, Boolean useLocalRpc, Boolean ignoreHomeMdb, GenericIdentity auxiliaryIdentity) at Microsoft.Exchange.Data.Storage.Management.XsoMailboxDataProviderBase..ctor(ExchangePrincipal mailboxOwner, String action) at Microsoft.Exchange.Data.Storage.Management.XsoDictionaryDataProvider..ctor(ExchangePrincipal mailboxOwner, String action, GetUserConfigurationDelegate getUserConfiguration) at Microsoft.Exchange.Management.StoreTasks.SetCalendarProcessing.CreateXsoMailboxDataProvider(ExchangePrincipal principal, ISecurityAccessToken userToken) at Microsoft.Exchange.Management.StoreTasks.SetXsoObjectWithIdentityTaskBase`1.InternalProcessRecord() at Microsoft.Exchange.Configuration.Tasks.Task.ProcessRecord() 0 Microsoft.Mapi.MapiExceptionUnknownUser: MapiExceptionUnknownUser: Unable to open message store. (hr=0x80004005, ec=1003) Diagnostic context: Lid: 55847 EMSMDBPOOL.EcPoolSessionDoRpc called [length=230] Lid: 43559 EMSMDBPOOL.EcPoolSessionDoRpc returned [ec=0x0][length=248][latency=0] Lid: 23226 --- ROP Parse Start --- Lid: 27962 ROP: ropLogon [254] Lid: 17082 ROP Error: 0x3EB Lid: 26937 Lid: 21921 StoreEc: 0x3EB Lid: 27962 ROP: ropExtendedError [250] Lid: 1494 ---- Remote Context Beg ---- Lid: 26426 ROP: ropLogon [254] Lid: 25805 Error: 0x0 Lid: 11752 StoreEc: 0x8004010F Lid: 19149 Error: 0x0 Lid: 25805 Error: 0x0 Lid: 11752 StoreEc: 0x8004010F Lid: 22787 Error: 0x0 Lid: 13800 StoreEc: 0x8004010F Lid: 9448 StoreEc: 0x8004010F Lid: 16454 Lid: 16966 StoreEc: 0x8004010F Lid: 31433 StoreEc: 0x8004010F Lid: 8620 StoreEc: 0x3EB Lid: 1750 ---- Remote Context End ---- Lid: 26849 Lid: 21817 ROP Failure: 0x3EB Lid: 26297 Lid: 16585 StoreEc: 0x3EB Lid: 32441 Lid: 1706 StoreEc: 0x3EB Lid: 24761 Lid: 20665 StoreEc: 0x3EB Lid: 25785 Lid: 29881 StoreEc: 0x3EB at Microsoft.Mapi.MapiExceptionHelper.ThrowIfError(String message, Int32 hresult, SafeExInterfaceHandle iUnknown, Exception innerException) at Microsoft.Mapi.ExRpcConnection.OpenMsgStore(OpenStoreFlag storeFlags, String mailboxDn, Guid mailboxGuid, Guid mdbGuid, MapiStore msgStorePrivate, String& correctServerDn, ClientIdentityInfo clientIdentityAs, String userDnAs, String applicationId, CultureInfo cultureInfo) at Microsoft.Mapi.MapiStore.OpenMapiStore(String serverDn, String userDn, String mailboxDn, Guid guidMailbox, Guid guidMdb, String userName, String domainName, String password, String httpProxyServerName, ConnectFlag connectFlags, OpenStoreFlag storeFlags, CultureInfo cultureInfo, Boolean wantRedirect, String& correctServerDN, ClientIdentityInfo clientIdentity, String applicationId, Client xropClient, Boolean wantWebServices, Byte[] clientSessionInfo, TimeSpan connectionTimeout) at Microsoft.Mapi.MapiStore.OpenMailbox(String serverDn, String userDn, String mailboxDn, String userName, String domainName, String password, ConnectFlag connectFlags, OpenStoreFlag storeFlags, CultureInfo cultureInfo, WindowsIdentity windowsIdentity, String applicationId) at Microsoft.Exchange.Data.Storage.MailboxSession.ForceOpen(MapiStore linkedStore)