BeMail: Launch returned attachments
Certain kinds of attachments, including the attached contents of returned e-mail, cannot be easily displayed by BeMail. The reason is that they use the Internet standard MIME type „message/rfc822,“ rather than the BeOS standard text/email.
You can fix the filetype of each attachment as it comes in by using the Open With / FileType dialog, but here’s how you can make the fix permanent:
Open up Preferences | FileTypes and add the MIME type rfc822 to the message group. Close FileTypes. Now navigate Tracker to /boot/beos/ apps and right-click on StyledEdit (you can’t do this from a link to StyledEdit). Choose Add-Ons | FileTypes and add the new message/ rfc822 type to its list of handled filetypes. Save and close.
Return to your BeMail message, click on the attachment link, and it’ll pop up in StyledEdit.