So for the past few days my emails have been coming in slow....on my iPod they come in quick, much quicker. I've noticed that I may or may not get it on my z10 now. I did the hard reset with the volume thingy yesterday but like right now I received an email and I got it on my iPod but still not on my z.
Sorry I didn't have my Z10 with me, I meant sync interval, as KermEd said, try changing the sync interval to 5 minutes. Note that will affect your data usage, so this may be an issue if you are on a limited data plan. Having said that I don't know how much data the sync takes up.