I have done this in two ways in the past:

- Way 1: Configure the iOS mail app and calendar apps to connect to your exchange server as well as your personal server. There are instructions on the web on how to do this. Then from that point on, you have two sets of emails and calendars inside your native iOS apps: Your work stuff and your personal stuff. At any time, You can view them both at the same time mixed together, or choose to view only one or the other of them.

- Way 2: Install the iOS version of Outlook (the actual app) on your iOS device. This is also what Andy suggested.


The former (integrating with iOS mail and Cal) works, but when I did it in the past, I would occasionally get problems such as:
- Not being properly notified when there was a password expiration, causing the synchronization to silently stop working altogether, so I would stop getting calendar updates but not realize it, and thus miss meetings and such.
- Bugs in their exchange support which caused synchronization to stop working and crash repeatedly in a rapid loop in the background invisibly, thus draining my phone battery unexpectedly.

The latter (just installing the Outlook app) is much more reliable, and you keep your iOS mail/calendar separate from your work mail/calendar. Though I cannot say if their calendar interface is any better. (Truth be told, I have not found a perfect calendar interface on a mobile device yet.)