Add the email sender.

Signed-off-by: Jan Losinski <losinski@wh2.tu-dresden.de>

sender.py

@@ -0,0 +1,39 @@
+import smtplib
+from email.encoders import encode_base64
+from email.mime.application import MIMEApplication
+from email.mime.multipart import MIMEMultipart
+from email.utils import formatdate
+
+
+class Sender:
+    def __init__(self, loop, from_addr, smtp_server, smtp_port, smtp_user=None, smtp_passwd=None):
+        self.from_addr = from_addr
+        self.loop = loop
+        self.host = smtp_server
+        self.port = smtp_port
+        self.user = smtp_user
+        self.passwd = smtp_passwd
+
+    def _send_mail(self, job, data):
+        msg = MIMEMultipart()
+        msg['Subject'] = job.title
+        msg['From'] = self.from_addr
+        msg['To'] = job.user.kindle_mail
+        msg['Date'] = formatdate(localtime=True)
+
+        mobi = MIMEApplication(data)
+        encode_base64(mobi)
+        mobi.add_header('Content-Disposition',
+                        'attachment; filename={id}.{format}'.format(id=job.article, format=job.format))
+
+        msg.attach(mobi)
+
+        smtp = smtplib.SMTP(host=self.host, port=self.port)
+        smtp.starttls()
+        if self.user is not None:
+            smtp.login(self.user, self.passwd)
+        smtp.sendmail(self.from_addr, job.user.kindle_mail, msg.as_string())
+        smtp.quit()
+
+    async def send_mail(self, job, data):
+        return self.loop.run_in_executor(None, self._send_mail, job, data)