.BOE File

File extension boe is mainly related to Microsoft Outlook Express, an e-mail and news client included in earlier releases of Microsoft Internet Explorer.

A .boe file represents compressed backup of email messages. Most likely no longer used file type.

How to open:

Some programs like ZipZag can still access the data from these backups.

How to convert:

It seems that you can recover the backup (.boe) only using the original version of Microsoft Outlook Express. However, these files may be simply ZIP files, so you can potentially extract them as such.