看上去最大是50G；
Outlook 2013 and Outlook 2010
Collapse this tableExpand this tableName 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)
Outlook 2007 and Outlook 2003
Collapse this tableExpand this tableName Type Valid Data Range Default
MaxLargeFileSize REG_DWORD 0x00000001 – 0x0000C800 0x00005000 20,480 (20 GB)
WarnLargeFileSize REG_DWORD 0x00000000 – 0x0000BE00 0x00004C00 19,456 (19 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)