Is there anything on iOS that would cause your mail pulls to be set to manual?

I had a user come in where I work, and she said that she didn't get emails on her iPhone 4; she was running iOS7. I have an iPhone 5c, and I failed to receive emails around 8:30 PM today.

Her issue was that in her settings her mail had been set to only update manually. When I checked my phone, mine had also been set to manual. They're both phones that have been setup recently, is that the default setting? Or does it get set when it is placed on do not disturb? I'm really concerned about this because both of us missed important emails.