Iphone

I have recently bought and iphone and am obviously able to access my email.  However I thought it should be in sinc with my email account but when I read and delete message via my phone when I log into my Hotmail account on a computer they are still showing as unread.  I have contact my mobile provider who has said everything is ok at their end and I should contact my email provider.  I am struggling to find a way of contacting Hotmail, hence this thread....any suggestions please