Problem with Exchange 2003 cluster backend SMTP resource.
I have front end and backend cluster exchange 2003. Every 4 or 5 hours the backend stops taking mails from front end and the queqe keeps on increasing on front end. When i telnet the backend server from front end server during the problem i get connected and when i issue mail from command i get 4.x error and out of memory and get's disconnected straight away with out any option. The only way i can get away with this problem is to take the SMTP resource offline and get it back online and when taking it offline the resouce doesnt go offline but goes with fail that means resource failure and then i get it back online again it works fine for 5 hours and the problem comes back again
I checked the MS KB which says to check the Vsi folder permission for system account and clarifeid it the permissions are in its place on the folder and sub folders still there is problem with it.
Can some throw some light on which could cause the problem?
Exchange 2003 SP2 enterprise with all patches clustered backend
Windows 2003 SP2 with all patches enterprise edition backend
Exchange 2003 SP2 enterprise and all patches windows 2003 enterprise all patches on front end