Exchange 2007 won't receive emails

If you stop receiving emails in Exchange 2007 telnet to your Exchange 2007 server.  Do you see the following error, “452 4.3.1 Insufficient system resources”?  You might also see this in the event log as 15002.  Exchange 2007 is smart enough to monitor your system resources so that it does not crash your server. 
You can change the configuration options of that here C:Program FilesExchange ServerEdgeTransport.exe.config
If you open this file you will see the global setting where you can disable it completely(not recommended).
 <gcServer enabled=”true” />
You can also see here where you can change each individual setting:

<add key=”AgentLogEnabled” value=”true” />
      <add key=”ResolverRetryInterval” value=”30″ />
      <add key=”DeliverMoveMailboxRetryInterval” value=”30″ />
      <add key=”ResolverLogLevel” value=”Disabled” />
      <add key=”ExpansionSizeLimit” value=”1000″ />
      <add key=”MaxIdleTimeBeforeResubmit” value=”12:00:00″ />
      <add key=”MailboxDeliveryQueueRetryInterval” value=”00:05:00″ />
      <add key=”QueueGlitchRetryInterval” value=”00:01:00″ />
      <add key=”QueueGlitchRetryCount” value=”4″ />
      <add key=”PFReplicaAgeThresholdHours” value=”48″ />
      <add key=”DeferredReloadTimeoutSeconds” value=”5″ />
      <add key=”MaxDeferredNotifications” value=”20″ />
      <add key=”MaxQueueViewerQueryResultCount” value=”250000″ />
      <add key=”RoutingConfigReloadInterval” value=”12:00:00″ />
      <add key=”DumpsterAllMail” value=”false” />
      <add key=”DumpsterAllowDuplicateDelivery” value=”false” />
      <add key=”DumpsterDeletionDelayAfterStartup” value=”00:02:00″ />
      <add key=”DatabaseCheckPointDepthMax” value=”20971520″ />
      <add key=”DatabaseMaxCacheSize” value=”134217728″ />
      <add key=”DatabaseCacheFlushStart” value=”3″ />
      <add key=”DatabaseCacheFlushStop” value=”5″ />
      <add key=”QueueDatabaseBatchSize” value=”40″ />
      <add key=”QueueDatabaseBatchTimeout” value=”100″ />
      <add key=”QueueDatabaseMaxConnections” value=”4″ />
      <add key=”QueueDatabaseLoggingFileSize” value=”5242880″ />
      <add key=”QueueDatabaseLoggingBufferSize” value=”524288″ />
      <add key=”QueueDatabaseMaxBackgroundCleanupTasks” value=”32″ />
      <add key=”QueueDatabaseOnlineDefragEnabled” value=”true” />
      <add key=”QueueDatabaseOnlineDefragSchedule” value=”1:00:00″ />
      <add key=”QueueDatabaseOnlineDefragTimeToRun” value=”3:00:00″ />
      <add key=”QueueDatabasePath” value = “C:Program FilesMicrosoftExchange ServerTransportRolesdataQueue” />
      <add key=”QueueDatabaseLoggingPath” value = “C:Program FilesMicrosoftExchange ServerTransportRolesdataQueue” />
      <add key=”IPFilterDatabasePath” value = “C:Program FilesMicrosoftExchange ServerTransportRolesdataIpFilter” />
      <add key=”IPFilterDatabaseLoggingPath” value = “C:Program FilesMicrosoftExchange ServerTransportRolesdataIpFilter” />
      <add key=”TemporaryStoragePath” value = “C:Program FilesMicrosoftExchange ServerTransportRolesdataTemp” />
      <add key=”EnableResourceMonitoring” value=”true” />
      <add key=”ResourceMonitoringInterval” value=”00:00:02″ />
      <add key=”PercentageDatabaseDiskSpaceUsedHighThreshold” value=”0″ />
      <add key=”PercentageDatabaseDiskSpaceUsedMediumThreshold” value=”0″ />
      <add key=”PercentageDatabaseDiskSpaceUsedNormalThreshold” value=”0″ />
      <add key=”PercentageDatabaseLoggingDiskSpaceUsedHighThreshold” value=”0″ />
      <add key=”PercentageDatabaseLoggingDiskSpaceUsedMediumThreshold” value=”0″ />
      <add key=”PercentageDatabaseLoggingDiskSpaceUsedNormalThreshold” value=”0″ />
      <add key=”PercentagePrivateBytesUsedHighThreshold” value=”0″ />
      <add key=”PercentagePrivateBytesUsedMediumThreshold” value=”0″ />
      <add key=”PercentagePrivateBytesUsedNormalThreshold” value=”0″ />
      <add key=”VersionBucketsHighThreshold” value=”200″ />
      <add key=”VersionBucketsMediumThreshold” value=”120″ />
      <add key=”VersionBucketsNormalThreshold” value=”80″ />
      <add key=”PercentagePhysicalMemoryUsedLimit” value=”94″ />
      <add key=”DehydrateMessagesUnderMemoryPressure” value=”true” />
      <add key=”VersionBucketsHistoryDepth” value=”3″ />
      <add key=”PrivateBytesHistoryDepth” value=”30″ />
      <add key=”CrashOnStopTimeout” value=”false” />
      <add key=”DnsFaultTolerance” value=”Lenient” />
      <add key=”PriorityQueuingEnabled” value=”false” />
      <add key=”MaxPerDomainHighPriorityConnections” value=”3″ />
      <add key=”MaxPerDomainNormalPriorityConnections” value=”15″ />
      <add key=”MaxPerDomainLowPriorityConnections” value=”2″ />
      <add key=”HighPriorityMessageExpirationTimeout” value=”8:00:00″ />
      <add key=”NormalPriorityMessageExpirationTimeout” value=”2.00:00:00″ />
      <add key=”LowPriorityMessageExpirationTimeout” value=”2.00:00:00″ />
      <add key=”HighPriorityDelayNotificationTimeout” value=”00:30:00″ />
      <add key=”NormalPriorityDelayNotificationTimeout” value=”4:00:00″ />
      <add key=”LowPriorityDelayNotificationTimeout” value=”8:00:00″ />
      <add key=”MaxHighPriorityMessageSize” value=”250KB” />
      <add key=”ByteEncoderTypeFor7BitCharsets” value=”1″ />