Gmail application is not updating automatically!

[BuTa]

how to turn on or off auto sync for account on xperia Z? 

[JakeSully]

sync area is under settings then accounts from there you edit sync for etc gmail, hotmail, and much more.

[Jake-SonyXperia]

You can also do the following.

Click Gmail application > Click Menu ( 3 squares) > Tap Settings > Tap Gmail account >  Tick Sync Gmail.

If Auto Sync is off, this will turn it on when you tick this option.