How to fake my android - Zuk-Z1 to look like Nexus 5x/ 6p
I had a similar issue to Vivek. This is what I tried and worked for me.

Before attempting, SEE NOTES. This assumes you are rooted.

So first I went to google playstore and downloaded a build.prop editor. I focused on these attributes for my Moto X Pure:

ro.product.model=XT1575
ro.product.brand=motorola
ro.product.name=clark_retus
ro.product.device=clark
ro.product.manufacturer=motorola
ro.build.fingerprint=motorola/clark_retus/clark:6.0/MPH24.49-18/18:user/release-keys
ro.build.product=clark
ro.build.host=ilclbld87
ro.build.version.security_patch=2016-02-01
ro.build.version.release=6.0


and changed them to match the Nexus 5x:

ro.build.version.release=6.0.1
ro.build.version.security_patch=2016-03-01
ro.product.model=Nexus 5X
ro.product.brand=google
ro.product.name=bullhead
ro.product.device=bullhead
ro.build.host=wpiy3.hot.corp.google.com
ro.product.manufacturer=LGE
ro.build.product=bullhead
ro.build.fingerprint=google/bullhead/bullhead:6.0.1/MMB29Q/2480792:user/release-keys


After making the changes. I saved and then rebooted. After that I installed Gmail (didn't have it before) and it automatically sent me a "Welcome Nexus 5x User" email after installing. That made me pretty confident that I was now viewed as a Nexus 5x, by that app at least. I added the new exchange account, entering my credentials and things worked.

Fini

Important Notes


Make a backup of your phone. Specifically a NAND backup. What this
means is to have a custom bootloader like TWRP and make a backup
there. 
Backup your original build.prop file and store somewhere.
Like on your SD card or computer. 
Make sure GooglePlay has auto-updates disabled. This might cause some issues as it tries to update your phone with new software revisions due to it thinking you are now a Nexus 5x 6.0.1 and need the latest and greatest software for each app you have installed.


Good Luck!