For vs While

new.py

import win32com.client

outlook = win32com.client.Dispatch("Outlook.Application").GetNamespace("MAPI")

inbox = outlook.GetDefaultFolder(6) # "6" refers to the index of a folder - in this case,
                                    # the inbox. You can change that number to reference

                                    # any other folder
messages = inbox.Items
message = messages.GetFirst()
rec_time = message.CreationTime
body_content = message.body
subj_line = message.subject

#--------- This works-----------------
#while message:
#	print(message.subject, message.CreationTime)
#	message = messages.GetNext()

#---------This doesnt ----------------
#for mess in range(message):
#    print(mess.subject, mess.CreationTime)