Outlook size limit for .pst .ost files

If you use Outlook with internet mailbox or with Exchange cached mode, outlook will use .pst or .ost file to store data.

Each of this files has his own maximum data limit supported by Outlook.
If this limit is reached .pst or .ost files are permitted to add any more data.

If outlook pst, ost file reach the size limit then you will get the warning.

Below, in table you can check maximum size limit, depended on Outlook version.


Outlook 2010

Name Type Valid Data Range Default
MaxLargeFileSize REG_DWORD 0x00000001 – 0x0000C800 0x0000C800 51,200 (50 GB)
WarnLargeFileSize REG_DWORD 0x00000000 – 0x0000BE00 0x0000BE00 48,640 (47.5 GB)
MaxFileSize REG_DWORD 0x001F4400 – 0x7C004400 0x7BB04400 2,075,149,312 (1.933 GB)
WarnFileSize REG_DWORD 0x00042400 – 0x7C004400 0x74404400 1,950,368,768 (1.816 GB)

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