Suppose you had made a presentation by working whole night for a board meeting, in morning you dressed up nicely, head to office and just before your meeting you realize that you forget to bring presentation created by you and its on your home computer, you called up your wife and ask her to email that file to you.
Your wife confirms that she had mailed you file but after 15 minutes you hadn’t got your file. Usually email will get delivered in 2-3 seconds but in your case its taking very long time, Thankfully email arrives just before meeting and everything went fine.
But do you wanna know why email get delivered late to you? Usually a email goes from a path, this path consist of several servers through which an email has too go. You an easily find the path of your email, just open header of your email and then you will find a Receive section in which you will find from where email has been sent and when you had got it.
These servers are responsible for delaying your email. So if you wanna know which server delayed your email then open your email then open its header (Show Original).