Try DBXtract

OE5 and OE6 have a proprietary binary format that makes archiving individual messages difficult. In addition, a number of people have indicated that their message folders have become corrupted and OE can not read them. Consequently, they have lost all the messages in that folder.

DBXtract.exe extracts all mail and news messages from individual dbx files. After extracting the messages one can drag them from a Windows Explorer folder into an Outlook Express mail folder.