import imaplib, serial, struct, time

class Mail():
    def __init__(self):
        self.user= 'USER'
        self.password= 'PASS'
        self.ser = serial.Serial('/dev/tty.usbmodem621', 9600)
        self.M = imaplib.IMAP4_SSL('imap.gmail.com', '993')
        self.M.login(self.user, self.password)

    def checkMail(self):
        self.M.select()
        self.unRead = self.M.search(None, 'UnSeen')
        return len(self.unRead[1][0].split())

    def sendData(self):
        self.numMessages= self.checkMail()
        #turn the string into packed binary data to send int
        self.ser.write(struct.pack('B', self.numMessages))

email = Mail()

# check for new mail every minute
while 1:
    print 'Sending'
    email.sendData()
    time.sleep(60)