Is it permissible for me to talk to a girl I love and correspond with her via email with the intention of marrying her in the future, knowing that I cannot get married currently?

A young man who is able to marry and bear its costs is advised to hasten to it whenever his soul yearns for it. As for communication between young men and young women, whether for the purpose of marriage or otherwise, it is a path to evil that must be blocked, because it may lead to falling into vice and incurring God's wrath. Allah has warned against following the footsteps of Satan. Therefore, any communication with a girl must be avoided until marriage takes place.