Here is the full firmware package of the new Marshmallow B571 update for your Huawei Ascend Mate 7 (MT7-L09). This firmware can be easily installed as an Update.app package on top of a wide range of builds.

Ascend mate 7

firmware details
Device: Huawei Ascend Mate 7
Model: MT7-L09
Android: Marshmallow v6.0
EMUI: 4,0
Firmware: B571
Build number: MT7-L09C432B571
Post Date: 07/23/2016
Region: Europe
Status: Official (stable)
Type: full firmware package
File name: update.zip
Download link: Download | Size: 1,2GB

How to install

Compatibility: This firmware should only be installed on European C432 based devices.

Download update.zip from the above mentioned link and extract it on your PC.
Transfer the extracted "Update.app" package to the phone's external microSD card's 'DLOAD' folder (create a new DLOAD folder if not already present).
Take a backup of your data using the Huawei backup app.
Disconnect the USB cable and turn off the phone.
Now reboot the phone by holding Vol Down + Vol Up + Power at the same time for a few seconds until the update starts.
official changes

Free space in internal memory
Reduce battery consumption
Director mode unavailability issue fixes
Fixed European calendar showing wrong number of days
Fixes for navigation bar blurring during full screen video playback
Fixes for muted playback on certain videos in WMV
Fix bugs in Google now on tap
Fixes a bug that caused problems sending MMS on certain networks