If you have multiple PST files and you want to merge them in one PST file, try Merge PST Tool to easily complete this task with a simple mouse click. It supports both ANSI and UNICODE PST file and merges multiple PST files in one PST file without any data loss. Visit here for more info: http://www.merge.pstfile.org/
owenpaul
How to merge bulk PST files into Outlook?