Install default Mail App on my Nexus 5 I do not see default mail App on my Nexus 5. I do have gmail though working fine. Probably I removed it earlier. How do I install it again ! I want to use that to configure Exchange Server on it to configure my official emails and calendars.

Currently when I try to do "Add Account" it does NOT show "Corporate" !
Try to install the Email app directly from Google Play Store.  If this app is shown as incompatible on your device, side-load it by downloading it from here, enabling the Unknown sources in Settings -> Security, and installing the apk (either by tapping the apk in the download manager, or via ADB from your PC: adb install -r &lt;path-to-apk&gt;).

Keep in mind though that this version sometimes breaks the Exchange functionality on some mostly non-Nexus devices. In order to resolve this, you need to also install a copy of latest Exchange2Google.apk app that is available for download from here or here. You don't have to install it as a system app, just side-load it in the same manner as described above.