Tap the Mail icon 
to start and select “Exchange” at the first screen:
*Note* You can also get to this screen by going to Settings > Passwords & Accounts > Add Account.
In the e-mail field enter your “first-initial+lastname@csenergy.com” (e.g. jsmith@csenergy.com), then tap “Next” at the top right and “Sign In” at the prompt:
Finally, enter the password for your main Conti Solar account (the same password you use to log on to your computer), “Sign in” and tap “Save” at the last screen.
Note: Your phone will initially be blocked from e-mail until the new device is approved by IT.
You can download and use the Outlook app instead of the Apple Mail app, however this app has a separate calendar. Apple Mail will utilize the Apple Calendar app.