mail_gen.py

>>> def generate(startdate, recipients, daycount, message):
...     last_date = startdate
...     mail = email.message_from_string(message)
...     msg_lib = []
...     for i in range(0, daycount):
...         for recep in range(len(recipients)):
...             mail['date'] = email.utils.formatdate(time.mktime(last_date.utctimetuple()))
...             msg_lib.append(mail)
...         last_date = last_date + datetime.timedelta(days=1)
...     return msg_lib
...     
... 
>>> f = generate(datetime.datetime.now(), ['me', 'you'], 4, "Hello!")
>>> from itertools import product
>>> g = product(f, repeat=2)
>>> all(x is y for x, y in g)
True