Not able to include Content-Type: text/calendar in multipart/alternative

[dilyanpalauzov]

Checklist

• [X] I have used the search function to see if someone else has already submitted the same bug report.
• [X] I will describe the problem with as much detail as possible.

App version

5.600

Where did you get the app from?

F-Droid

Android version

8 (Lineage OS)

Device model

Xiaomi Mi5 Plus

Steps to reproduce

As discussed at https://gitlab.com/techbeeat1/jtx/-/issues/277, an Android application sends Intends and creates an email in K9, which has this structure:

Content-Type: multipart/mixed
  Content-Type: multipart/alternative
    Content-Type: text/plain; charset=utf-8
    Content-Type: text/html; charset=utf-8
  Content-Type: text/calendar

The structure shall be instead:

Content-Type: multipart/alternative
  Content-Type: text/plain; charset=utf-8
  Content-Type: text/html; charset=utf-8
  Content-Type: text/calendar

The author of the application says he uses the Android API correctly, and it is the Email application, which does not create the correct MIME structure.

Expected behavior

Not applicable.

Actual behavior

Not applicable.

Logs

Not applicable.

[cketti]

There is no Android Intent that supports the case you're asking for.

[dilyanpalauzov]

I see. Is there an Android intent, which can create email with Content-Type: text/calendar; method=REQUEST; component=VTODO?

According to the author of an Android application this in the responsibility of the email application — https://gitlab.com/techbeeat1/jtx/-/issues/276.

[cketti]

We intend to improve interoperability with calendar apps in the future. Right now there's nothing a calendar app can do to get K-9 Mail to send iMIP messages.

I believe the same is true for other email apps on Android.