buildin an smtp client in python . which can send mail , and also show that mail has been received through any mail service for example gmail !!
Depends what you mean by "received". It's possible to verify "delivery" of a message to a server but there is no 100% reliable guarantee it actually ended up in a mailbox. smtplib will throw an exception on certain conditions (like the remote end reporting user not found) but just as often the remote end will accept the mail and then either filter it or send a bounce notice at a later time.
How would one build an smtp client in python?