Hi, I guess the people who got upset are those whose email got delayed hours (that tiny percentage of users which amounts to some dozens). "A 2.6sec delay" is

Hi, I guess the people who got upset are those whose email got delayed hours (that tiny percentage of users which amounts to some dozens). "A 2.6sec delay" is just the median (as per the OP), that leads nowhere if you do not know the mean or other statistics. Which was the maximum delay? Just trying to clarify that the fact that you are not upset does not mean the 50% people above 2.6 secs should not.