If you’re having trouble opening an Outlook PST file and it is around 2GB in size, you’re probably hitting an old legacy limit.   

Older versions of Outlook had this as a set limit due to constraints based around the FAT file system used at the time.   It appears some Outlook related tools still have this limit.

The situation here is that we’ve just run a restore of an old PST file (dated 2008) which is 2,112,536,576 Bytes.    Now although this file was created using Outlook, it now appears that Outlook is unable to open it as it’s corrupt.

Fine – we can use scanpst.exe (inbox repair tool) to repair it?   Nope…    It appears that the file is around 25MB over the limit that scanpst.exe can handle!   The last error in the logfile to signify this is “80040834” (obvious error!)

In a bizarre twist – MS have released a tool which will shrink the PST file to a size compatible with scanpst.   The only drawback is that the tool basically “DELETES” 25MB of the mailbox to shrink it’s size!!

Yup, you read that correct.   The scanpst from Microsoft, can’t read the mailbox created by Outlook (from Microsoft) without deliberately deleting valuable data!

At least in this case the resulting mailbox had the necessary emails the client was looking for.

Just make sure if you generate .pst exports – you keep the size under 2GB

Here’s a link to the tool which “compacts” the pst file for you: