How do I open MIME attachment on iPhone 7?
How do I open mime attachment?
[Re-Titled by Moderator]
iPhone 7, iOS 15
You cannot. A Mime attachment is a Microsoft Outlook proprietary format. Usually happens when Outlook does something weird to the attachments that causes them to be packed in a mime attachment bundle. Such attachments cannot be unpacked by the iPhone's default mail App.
You may be able to use a 3rd party app like Eml Viewer
https://apps.apple.com/us/app/eml-viewer/id1232389519
Or Winmail
https://apps.apple.com/us/app/winmail-viewer-letter-opener/id411897373
to open such attachments by sharing the email to the app.