PST File Size Limits



I would love to have anyone share their experience with PST file size. The
link to the following article states
that in Outlook 2003 and 2007, the default configuration for a PST is 20
GB!!! The IT folks where I work are questioning the accuracy of the article.
I will send feedback to, but I'm curious to know what
experience anyone can share about file corruption and/or size limits with
Many thanks!


we have people with 10 gig pst files running fine. Why don't you believe the
limit is 20 gig? File corruption is more a function of where the pst is
stored and how many thunderstorms you have in our area.
I suspect your IT department "scares" users into managing their email file
sizes with stories of corruption.

Oliver Vukovics [Public Shareware]

Hi suejay,

there are different numbers on different websites available for the new PST

Microsoft write the limit is ~20GB.


you will get the information:

"Increase in maximum size of PST/OST files to a theoretical 33TB;
administrator can control size with a policy. New file format also supports
Unicode; see:"

On this german website of an "Ex-MVP for Outlook, (Mr. Folke Kieseler) you
get the number:
4.294.967.295 MB (ca. 3,9 TB)

We create a PST file with 450 GB and share this with several users, so 20GB
is definily not the limit.


The 20GB size limit is just a default configuration for PST
file,which,Microsoft states,is a optimal value for the maximum PST size.Of
course you can change this value to what you want,but note you're coming up
against the performance problems as the PST file grows up.
Aug 16, 2023
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Actually, Outlook provides only 2 GB of storage in its earlier versions. But after analyzing the requirements of the users it was increased up to the 20 GB after versions of Outlook 2003. But that was not enough. Then Outlook decided to move with the 50 GB of space and it is till now. These are the PST file size limits if you are facing any issues with the PST file size then you can use SysTools PST Splitter Tool to split the PST file into smaller parts.
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