This function returns a text with the email of the user in argument user_name.
Argument user_name is a string with a user name, not to be confused with the user's full name.
Syntax
userEmail(text user_name) #Output: Text
This function returns a text list with the emails of the users in argument user_names.
Argument user_names is a string list with user names, not to be confused with users' full names.
Syntax
userEmail(text list user_names) #Output: Text list
