Refactor: renamed some variables
Refactor: Extracted a helper to try to improve readability
Refactor: Moved split to a utils library
Refactor: Renamed split method and changed its signature
It ignores spaces around email addresses. I got trim code from StackOverflow
Refactor: now using VectorUtils::map function to trim all email addresses
Refactor: Extracted trimming to a helper method
Refactor: added a wrapper for split to have a more convenient signature