EML
EML is the industry standard email message format used by several email clients including Outlook Express. .eml extension is reserved extension used for email files, which are created to agree with RFC 822 standard. In other words, these are the text files having RFC 822 standard. Outlook Express can view and send EML messages as SMTP/MIME messages. Such files can contain email messages, attachments or files sent with the email. If you need to view the file using Internet Explorer, you will need to convert it in MHT format.
DBX
DBX (DataBase eXtension) is the file format used by Outlook Express 5.x and 6.x to store email messages of proper email folder. Each file contains messages of appropriate message folder. For instance, Inbox.dbx is the file containing messages of Inbox folder. All the files are consisted in a single root folder called Store Folder. Also known as Store Root, it is the hidden folder comprising of DBX files together with local IMAP and Hotmail messages and folders. The Folders.dbx file serves as the master index file for the entire store. Few other DBX files are:
- Offline.dbx to store IMAP and Hotmail tasks that are carried offline
- Pop3uidl.dbx that is responsible for tracking email messages that left on POP3 mail server
.dbx is the file to represent newsgroup folder
MBX
MBX files are Outlook Express 4 files that perform analogous tasks as DBX files do in later versions. The only difference is that Outlook Express uses separate file for each mailbox folder when saves as DBX files. Thus, the files of Outlook Express 4.x are Inbox.dbx, Sent Items.mbx etc.
Stellar Phoenix Outlook Express Recovery can restore all damaged DBX files and restore them .eml or .dbx folders. After repair, .eml files can be directly viewed in Outlook Express, whereas .dbx files need to be imported.