What is DBX File Format?


DBX is a mail file format used by Microsoft Outlook Express desktop-based email client. The file saves a collection of each email folder. These folders contain the email messages that are stored in a specific mailbox.

Every mailbox present in Outlook Express has its own DBX file extension. For example, Inbox is having inbox.dbx file, sent mail will have sent.dbx, drafts.dbx, deleted items.dbx, etc.

DBX folders should be opened only in Outlook Express. However, several other programs through the conversion can support opening these files.

DBX File Structure

Outlook Express DBX file structure displays a basic hexadecimal arrangement. The header portion is known as file signature that can be shown in the starting having hex value: CLSID, i.e. content class ID. It is an identifier that helps to differentiate DBX file type. It is mainly a string type that helps to define the respective file on OS.

When you closely observe DBX file structure, it shows that while deleting any message there is a trace that left behind. When a message is deleted, in the header block, 0x0200/0x01fc and the data block length are updated that reflect the deletion.

DBX File Specifications

File Type – Email Folder

Primary Association – Outlook Express

Company – Microsoft

Extension – .dbx

Identifying Characters – CF AD 12 FE

Technical Information about DBX File

There are some specific functions that are stored along with DBX files at a time of saving all emails and update system settings. These functions are mentioned below –

Mail folder.dbx – Every mail folder of Outlook Express is having a file with .dbx extension.

Folders.dbx – It represents an index of complete Outlook Express files. These files are recorded in formatting of the entire folder.

Inbox.dbx – It is the default email folder of Outlook Express. If this file is deleted, Microsoft automatically creates it. There are other DBX files related to it like Outbox.dbx, drafts.dbx, deleted.dbx, and sent.dbx.

POP3uidl.dbx – It is a collection of pop3uidl letter information. For example, all the parameters of which the letters on the server have been received and the ones that have not should be reserved on the server are recorded in pop3uidl.dbx.

Offline.dbx – It is for the email account that is configured with IMAP configuration.

News group name.dbx – It is similar to other folders and each snews group is saved as .dbx file.