Total size of messages

• Total number of messages
• Type of attachments
• Total number of messages with attachments
• Type of attachments

Here are the results of a large Outlook Data File (PST) that has been archived at each level of compression. The details of the PST file are as follows:

Personal Folders files (.PST) are compressed anyway. The following table demonstrates this as when all messages contained in the .PST file were converted to .msg files, the space taken up by the .msg files increased by 33% (from 717,888KB to 956,650KB). The rates of compression outlined in the table below show the space saving on the already compressed messages in a .PST file. Even more significant disk space savings are realised when compared to messages stored as individual .msg files on your hard drive (a further 15%).

Attachments in this PST file are both compressed (zip, pdf etc) and uncompressed formats.

When messages are archived with E-Rkive, details about each message are stored in a database (EmailArchive.dat). Each message is then saved as an individual file into the same location as the database. This means that you only open the actual message file when you double click on a message in the list to open the message. All other functions within E-Rkive use the data stored in the database.

For the above example, the database size is 45,368 KB. This is represented by the Yellow section in the graph below. There is no database in the PST file because you are working with the actual messages.

The Blue section shows messages with attachments, the Red section indicates messages without attachments.

The graph demonstrates that as the level of compression increases, the less effect it has on messages with attachments (for this particular example anyway).

NOTE: Results of archived PST files will vary greatly, depending on what types of messages are stored in them. This example merely displays results that can be achieved with a large PST file. Attachments that are already compressed will not compress much more.

The archiving was only performed once. The archive was then recompressed to each level. The recompression process for 11,425 messages took around 20 minutes with the archive stored on the local hard drive.