If an email (which for the purpose of this elaboration may be denoted as top level mail) has been forwarded as an attachment from Microsoft Windows based computer, the mail attachment takes the form of a ".eml" extension file format. The mail attachment appears as "mime-attachment" inside the top level mail body when viewed on the iPhone. The native mail App on iPhone is unable to read such ".eml" file format mail attachments (referred to as first level attachment) correctly and behaves erratically. When the "mime-attachment" is opened inside the native mail App on the iPhone by tapping on it, it opens up to display the mail text contained inside it. If the "mime-attachment" also contains any file attachment (like a pdf file or a word file or a jpg file), the file attachment shows at the bottom of the mail body. However, if we now tap on any of those attached pdf/ word files, these files do not open and instead we get the message "Mail cannot open this attachment". This problem of pdf/ word file not opening does not occur if these files are not inside a "mime-attachment" and are an attachment in the top level mail itself wherein the pdf/ word files open up when tapped upon.
To summarise, it can be stated that although the ".eml" file or "mime-attachment" is getting opened since iOS 9.2. But after the "mime-attachment" is opened, the pdf/word/ image files inside that ".eml" file or "mime-attachment" is still not readable or openable by the native mail client on iOS 9.2. Kindly resolve the issue at the earliest so that the pdf/word/image attachments inside any recursively forwarded or multiple times forwarded mail (as attachment in the form of an ".eml" file or "mime-attachment") are readable by the native mail app on iOS without any problem
Steps to Reproduce: Forward as an attachment (not inline), any email with some text in mail body and pdf/ word file attached to it, using Outlook or any other Mail client to an email account which is configured on the iPhone. Open the received mail inside the native Mail App on the iPhone. The mail will open with the mail body text and the "mime-attachment" at its bottom. Tap on the "mime-attachment" which will open the "mime-attachment" to display the mail body text inside it alongwith the pdf/ word file inside it. Now tap on the pdf/ word file. This tap on the pdf/ word file will display the error message "Mail cannot open this attachment".
Expected Results: When the pdf/word files are tapped as described above, they should also get opened in the viewer from inside the native Mail App. Actual Results: The error message "Mail cannot open this attachment" is displayed.
Version: Native mail App in iOS 9.2 on iPhone