#12448: merge with 3.2.

Lib/smtplib.py

@@ -940,6 +940,7 @@ if __name__ == '__main__':
 
     def prompt(prompt):
         sys.stdout.write(prompt + ": ")
+        sys.stdout.flush()
         return sys.stdin.readline().strip()
 
     fromaddr = prompt("From")

Misc/NEWS

@@ -311,6 +311,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #12448: smtplib now flushes stdout while running ``python -m smtplib``
+  in order to display the prompt correctly.
+
 - Issue #12454: The mailbox module is now using ASCII, instead of the locale
   encoding, to read and write MH mailboxes (.mh_sequences files).