Don't merge my suggestion with this.
It's not each mail received what I want to code but each different accounts that one has configured within outlook.
Again, down load Blue Mail to your smartphone and configure 2 or more mail accounts. FOR EAch one YOU CAN define a color and mails are received separately or all together that way you can check mail based on area of interest or priority.
I have, for instance, one gmail account for all sites I visit that asks me for an email in order to try a software demo or so, and my personal relevant Hotmail account. Also have my job account.
So merging my suggestion with color coded messages received is not what I intended.
best way to describe is taking a look into Blue Mail App
Similar to PC versiones block users, unwanted MAIL, delete MAIL, move mail, etc.
App icon for all Apps should be able to get a particular color assigned by the user it makes easier to identifiy it many incons are green or blue