How can phone and laptop show different email histories?

[AC Question]

Apparently this is happening to more people than just me, but I can't find an answer. First, I noticed that an email I sent from my phone using gmail did not show up on my laptop in the sent folder but is in the sent folder on my phone. Weird. Then I noticed that all my sent email were erased from my phone but not my laptop gmail. Weirder. Finally, I noticed that my work account (Outlook) received an email in my inbox there that didn't show up on my phone. What is going on? I will post this in gmail and outlook help also...

 

[B. Diddy]

Welcome to Android Central! Are you using the Gmail app on your phone and the Gmail web interface on your computer? Or the stock Email app on the phone and an email client on your computer?