remove protection for msg and its attachment behavior

[zhang13634419004]

MIP SDK version

1.13.187

Developer environment

Windows

Issue Details

When we use mip sdk IFileHandler.RemoveProtection() for msg file. the pptx attachment's protection will be removed, the msg attachment's protection will be kept.
After adding a new option "container_decryption_option", "All", the result is still the same, seems this option doesn't work.

File	Label Type
msg file	Let users assign permissions when they apply the label
pptx attachment	Let users assign permissions when they apply the label
msg attachment	Let users assign permissions when they apply the label

Question

1. Does this default behavior work as expected?
   • office attachment's protection will be removed
   • msg attachment's protection will not be removed.
2. container_decryption_option doesn't work, is this a bug?

---

Document Details

⚠ Do not edit this section. It is required for learn.microsoft.com ➟ GitHub issue linking.

• ID: d28b11a9-799a-33cd-414d-4e421cefab93
• Version Independent ID: 74e2ee51-475b-fc09-c479-a596e6b367f0
• Content: How to - process email messages using MIP SDK
• Content Source: mip/develop/concept-email.md
• Service: information-protection
• GitHub Login: @msmbaldwin
• Microsoft Alias: mbaldwin