Microsoft Outlook 2007 and Outlook 2010 OST Corruption from time to time


I have an issue with a OST file constantly becoming corrupt and needs to be deleted and a new one regenerated

The Setup is Exchange 2003, and there are two clients that are having this issue, a 2007 one constantly and a 2010 outlook, only once at this stage

It can go for a few weeks without happening and then do it

The OST is about 5-6Gb in size

Thanks Adam

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OST File Size in 2007 and 2010 have a maximum size of 20GB.
Although at 5-6 GB you may see some performance issues, corruption not likely due to size.

When you say corruption, are the users actually getting a msg that says the file is corrupt or some other msg.
If not getting a msg what are the users seeing as being corrupt?

I might check that both Users have the latest SP installed for thie Office Suite

Office 2007 SP2

Office 2010 SP1

I know there were some performance issues that were directly related to outlook pst and ost files in 2007
These were addressed in the Service Packs

There were certainly some performance issues that were fixed in Office 2010 SP1

Is there any reason why these users are using cached exchange mode?
Are these Laptop Users?
Do they take their PC away from the Office and require offline access to their Mail?

If not, the ideal thing is to just turn off cached exchange mode.
You wont have any issues with the ost then.

If cached exchange mode is required:

I would start to look at the location of where these OSTs are stored?
Are they being stored in their default locations?
Or are they being stored somewhere else on the PC?
Are they Being Stored on a Shared Network Drive or location.

If they are stored on a Network share, move them back to the users local PC.
Corruption is common for psts and osts stored on netwrok locations.

Would also look to see if these users are syncing their outlook with  Mobile Devices such as Iphone or Ipad.
As these devices could be the soruce of the "Corruption"
If they are, turn off the outlook sync with these devices and test so that they may be ruled out.

Last but not least would also look for any antivirus that might be scanning them.
Antivirus scanning on PSTs and OSTs can also cause corruption.
If there are antivirus applications scanning these files, turn off or add an exception for these stored locations.

Let us know how you get on

I would seriously archive some of the data in that mailbox.....

And have you done a disk check within windows to see what it reports?

From an Elevated CMD prompt....

(NO switches yet)

If it reports that it cannot continue in Read Only mode, enter 'chkdsk /f /r', and hit 'Y', and reboot to allow the scan to complete. The log is in the Application log, source "Winlogon".
My experience has led me to beleive that Outlook in cached mode will perform best with a mailbox size of less than 1GB. The larger it gets the slower it performs and eventually you end up with a  OST file.

The only way to feasibly and effectively use a 5GB mailbox (imho), is in Online mode or by using Outlook Web Access.
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corrput OST file*
cdsausAuthor Commented:
I am going to Check the Service pack Levels on Office etc and see if that fixes it

I will update once this is complete

cdsausAuthor Commented:
I am still working on this but i think the Serive Pack is going to fix it as i am not sure  what service Pack he has on and i am sure it is a not current so this solution should do it, saying that the other two options i am also agreeing with the OST being very big and they need to look at cleaning it up.

Thanks for all your help, i will POST the end result once it is complete

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