Why Do I Have To Convert My Email?

When you buy a new DVD player you don’t have to convert all your DVDs to match the new player’s format, so why in the world do you need to convert your emails to use a new email program? It seems like such a simple thing–email. Why all the complexity? In some ways the answer is simple, email program developers want you to use their email program and make it as difficult as possible to move. On the other hand, the technology behind what an email is and how it’s read and stored explains why conversion is necessary.

What Email Formats Exist Today?

Behind the nice emails sitting in your Inbox to be read, forwarded and searched lies a complicated layer of coding and protocols that allow various types of data (audio, video, text, pictures…) to be presented and communicated across the internet. These include MIME, HTML and others. Each email program translates, displays and stores this data (read your email) in a different way. To denote this each email program uses a different email format or file extension (.XXX) to store your email data. The most common email formats are:

  • DBX – used by Outlook Express
  • MBOX – used by Apple Mail and Thunderbird
  • EML – used by Windows Live Mail, Vista Mail, and Gmail
  • PST – used by Microsoft Outlook
  • RGE – used by Microsoft Entourage
  • OLM – used by Microsoft Outlook for MAC (also uses PST)

Most of ConvertMyEmail’s customers are switching between PC and MAC, so let’s take a closer look at the top two email formats from which customers are converting: DBX and PST.

DBX (Outlook Express)

Most users assume that Outlook Express is a simplified version of Outlook, however, that is not the case. Outlook Express is built on an entirely different code base and does not align with the programing architecture of Outlook. If you want to get really technical you can read all about Microsoft’s proprietary email attachment format called Transport Neutral Encapsulation Format (link will take you to Wikipedia), which isn’t understood by Outlook Express.

Outlook Express stores all email messages and associated data as DBX files. Each mail folder in Outlook Express is a separate [name].dbx file. For example, your Inbox is stored as inbox.dbx and sent as Sent.dbx. Folders.dbx keeps the master list (or index) of all your folders and mailboxes. DBX only contains email information and attachments. Contacts, calendar and other information are stored separately. The DBX format of stored email data is unique to Outlook Express.

PST (Outlook)

Microsoft Outlook uses a .PST file extension to store you email data. PST stands for personal storage table, but is often referred to as a personal file folder. This personal file folder contains all data from your Outlook account including email, tasks, calendar, contacts, notes and journal entries. Depending on the version of Outlook you have there may be limits on the amount of data that can be stored in a single PST file. Older versions of Outlook (2000 and 2002) used the ANSI format to store data and was limited to a maximum of 2GB. Newer versions of Outlook use the Unicode format and have a maximum storage range of 20 – 50 GB depending on the version.

And Why Can’t I Just Import Those Files to My New Computer?

Moving your email data to a new computer is really easy if you intend to use the same email program. Most have a simple backup feature to store your data so it can be transferred and imported on your new computer. But, if you decide to switch to MAC, which the vast majority of our customer do, and want to use Apple Mail, DBX and PST are not readable formats. To work properly the data (email information, contacts, appointments…) within each of these file formats has to be rearranged (converted) into a format that your new email program can understand.

Perhaps one day these formats will be a thing of the past. For now ConvertMyEmail hopes to make the process of converting your email as easy and painless as possible.