pstconv

A java command line tool to convert proprietary Microsoft Outlook OST/PST files to EML or MBOX format, even if the file is password protected. OST/PST content is parsed and extracted with java-libpst library.

Requirements

• Java Runtime Environment 8

Usage

usage: java -jar pstconv.jar [OPTIONS]
 -e,--encoding <ENCODING>   Encoding to use for reading character data.
                            Default is ISO-8859-1.
 -f,--format <FORMAT>       Convert input file to one of the following
                            formats: mbox, eml. Default is mbox.
 -h,--help                  Print help and exit.
 -i,--input <FILE>          Path to OST/PST input file. Required option.
 -o,--output <DIRECTORY>    Path to MBOX/EML output directory. If it
                            doesn't exist, the application will attempt to
                            create it. Required option.
 -v,--version               Print version and exit.

For example, the following command will convert File01.pst to MBOX format, saving the results to a directory named 'mailbox':

$ java -jar pstconv.jar -i File01.pst -o mailbox

After the conversion is finished, you can use a free software like Mozilla Thunderbird in combination with ImportExportTools NG add-on to import the 'mailbox' directory to the e-mail client mailbox and view the converted messages. According to ImportExportTools NG plugin documentation, the import should work with either MBOX or EML formats, but we only tested it with MBOX:

1. Right-click on the 'Local Folders' entry to popup the context menu and select the 'Import mbox file' option as shown in the following image;

2. On the 'MBox Import dialog', select the option 'Import one or more mbox files, with its/their subdirectory'. Hit the 'OK' button and a open file dialog is shown to allow to select the mbox file. To import all messages from the converted "mailbox" directory, select the file 'Top of Personal Folders' located on the root of that directory. Click on the 'Open' button to start importing the 'mailbox' directory (it may take a while depending on the number and size of the messages);

3. After the import is finished, a new directory named 'Top of Personal Folders' is added to the 'Local Folders' entry containing all messages from the 'mailbox' directory.

The tool also adds a custom header named 'X-Outlook-Descriptor-Id' to each converted message containing the value of the descriptor id from the original PST message, so that's possible to compare both messages if needed.

How it works

The following flowchart diagram tries to explain the sequence of steps taken by pstconv tool to convert the input PST file.

Performance

We have randomly selected 12 PST files from real forensic cases with sizes ranging from 200MB to more than 3GB. We ran the pstconv tool 20 times to convert each selected file to MBOX and EML format (10 times each). The average results are shown in the following tables.

MBOX

File Name	Size (MB)	Msg Count	Time (sec)	Msgs/sec
File01.pst	181	743	6.9	107.3
File02.pst	299	1126	11.6	96.8
File03.pst	554	978	19.3	50.7
File04.pst	632	1198	21.2	56.4
File05.pst	770	1388	21.0	66.1
File06.pst	1033	3045	34.8	87.6
File07.pst	1162	4393	36.1	121.6
File08.pst	1365	3122	41.7	74.8
File09.pst	1849	3432	59.7	57.5
File10.pst	1979	10460	68.1	153.6
File11.pst	2771	2745	89.6	30.7
File12.pst	3477	3451	115.0	30.0
Total	16072	36081	525.0	77.8 (avg)

EML

File Name	Size (MB)	Msg Count	Time (sec)	Msgs/sec
File01.pst	181	743	42.5	17.5
File02.pst	299	1126	67.9	16.6
File03.pst	554	978	134.7	7.3
File04.pst	632	1198	139.6	8.6
File05.pst	770	1388	151.5	9.2
File06.pst	1033	3045	224.8	13.6
File07.pst	1162	4393	238.6	18.4
File08.pst	1365	3122	274.9	11.4
File09.pst	1849	3432	392.0	8.8
File10.pst	1979	10460	424.2	24.7
File11.pst	2771	2745	611.0	4.5
File12.pst	3477	3451	762.4	4.5
Total	16072	36081	3464.2	12.1 (avg)

The performance results show that converting a PST file to MBOX format is about 6.5 times faster than converting to EML format.

Building

To build this project you need:

• Java Development Kit 8
• Apache Maven 3.6.x

Assuming all the tools can be found on the PATH, simply go to the project directory and run the following command:

$ mvn -B package

Releasing

Go to the project directory and run the following commands:

$ mvn -B release:prepare
$ mvn -B release:perform -Darguments='-Dmaven.deploy.skip=true' 

It will automatically assume the defaults for each required parameter, namely, releaseVersion and developmentVersion. If it's necessary to control the values of each version, the release:prepare command can be run as follows:

$ mvn -B release:prepare -DreleaseVersion={a release version} -DdevelopmentVersion={next version}-SNAPSHOT