Intrigued by this question, I searched in the forums and found a similar query,which probably explains, at least in part, of what you are seeking.
Preventing installed apps from making calls or sending SMS
Almost verbatim from the answer by @ Steven Roose (all credits to him)
Developers sometimes grant their apps permission which their apps in fact don't need. If you are aware and you don't agree with this trend, the only thing you can do is not download such apps. Or even better, you can consider contacting the developer of the application and ask him why this permission is required. Maybe they are not aware of the fact and are very willing to remove the permission if they can please their users by doing so.
A to-do list should not have the permission to send SMS messages, if I see a to-do app that requires this permission myself, I would just look for another app to use.
My "guess", is that app developers ask for them just in case it is required in future, though the app may not need or use them currently. It might even be that the developer has requested an inclusive permission (for example,
android.permission.WRITE_EXTERNAL_STORAGE implies that
android.permission.READ_EXTERNAL_STORAGE has also been granted, and both permissions will show up for the app); although this might not be true in your case.
Also, one point: It might be a device-specific or case-specific (one-time) issue. Try uninstalling and reinstalling all relevant apps to check.
ELEPONE 8000 runs a custom ROM as per Android Authority.
"The Elephone P8000 runs Android 5.1 Lollipop out of the box, with the custom Elephone UI on top"
ROM appears to be Flyme as per this forum (search for Flyme)
Does this explain the discrepancy of app displaying different permissions as discussed in comments to the question?
As tested by Andrew T, I have repeated that by downloading from play store and the app does not have "send MMS " or "send email" permissions accorded. This leads to the conclusion that the observations made by OP are ROM / UI specific.
Reasons for the ROM/UI causing this could be a topic for separate question