There are two methods to deploying up to two email accounts on a single device. The following methods are applicable to iOS and Android devices.
Different Email Clients
If you are currently using AirWatch Inbox, a second email can be configured using another email client.
Using Native Email
Using the native email, an identical account cannot exist. It is possible, however, to hard-code a secondary account on the same domain but with a different username.
Note: Additional accounts will need to have hard-coded values for domain/username/email.