adress1@gmail.com othermail@pri.com 2014-03-31T13:24:04Z 555555
adress2@gmail.com othermail2@pri.com 2014-03-31T13:36:19Z 555555

cat file.csv |sed 's/[0-9]T[0-9]/[0-9] [0-9]/g'

adress1@gmail.com othermail@pri.com 2014-03-3[0-9] [0-9]3:24:04Z 555555
adress2@gmail.com othermail2@pri.com 2014-03-3[0-9] [0-9]3:36:19Z 555555

2014-03-31 13:24:04Z

sed 's/([0-9])T([0-9])/1 2/g' file.csv

awk '{sub("T", " ", $3)}1' file.csv