.DBX – Outlook Express Email Folder .EMAIL - Outlook Express Email Message .EML - E-Mail Message .IDX - Outlook Express Mailbox Index File .MBX - Outlook Express Mailbox .MIM - Multi-Purpose Internet Mail Message File .MIME - Multi-Purpose Internet Mail Extension .MS-TNEF - MS Transport Neutral Encapsulation Format .NCH - Outlook Express Folder File .ODS - Outlook Express 5 Mailbox (not to be confused with OpenDocument spreadsheet file) .OEB - Outlook Express Backup Wizard File .PAB - Personal Address Book .PST - Outlook Personal Information Store File .SIG - Signature File .VCF - vCard File .WAB - Windows Address Book