This function is only available for the Advanced plan.
While composing an email, you can check the references for the email and return to where you were.
View other content while composing an email
Mobile
- Swipe down the gray bar at the top center of the screen that you are composing an email on.
- If you want to return and continue composing your email, tap
shown above 
. - If there are multiple windows in use, tap the one you want to continue composing.
You can display up to 5 windows.