WHAT IS MY SMTP HOST NAME FOR MY IPAD AIR 2

What should i fill in on my iPad Air 2 with wifi and cellular data (acct is thru Sprint)

i dont know that to put for the host name. Everytime i log in to my ipad and go to Mail app, it

starts and continues to go thru each of my 10 email accounts (i think that is how many i have)

aand wants me to enter the passwords of each of them EVERYTIME. HOW CAN I STOP THIS

AND CARRY ON? ANY HELP WHATSOEVER WOULD BE VERY MUCH APPRECIATED!

THANKS GUYS!