Send a rather basic email notif

Also pep8 fixes

synapse/config/emailconfig.py

@@ -0,0 +1,62 @@
+# -*- coding: utf-8 -*-
+# Copyright 2015, 2016 OpenMarket Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# This file can't be called email.py because if it is, we cannot:
+import email.utils
+
+from ._base import Config
+
+
+class EmailConfig(Config):
+    """
+    Email Configuration
+    """
+
+    def read_config(self, config):
+        email_config = config.get("email", None)
+        if email_config:
+            self.email_enable_notifs = email_config.get("enable_notifs", True)
+            if (
+                "smtp_host" not in email_config or
+                "smtp_port" not in email_config or
+                "notif_from" not in email_config
+            ):
+                raise RuntimeError(
+                    "You must set smtp_host, smtp_port and notif_from "
+                    "to send email notifications"
+                )
+
+            self.email_smtp_host = email_config["smtp_host"]
+            self.email_smtp_port = email_config["smtp_port"]
+            self.email_notif_from = email_config["notif_from"]
+
+            # make sure it's valid
+            parsed = email.utils.parseaddr(self.email_notif_from)
+            if parsed[1] == '':
+                raise RuntimeError("Invalid notif_from address")
+        else:
+            self.email_enable_notifs = False
+            self.email_smtp_host = None
+            self.email_smtp_port = None
+            self.email_notif_from = None
+
+    def default_config(self, config_dir_path, server_name, **kwargs):
+        return """
+        # Enable sending emails for notification events
+        #email_config:
+        #   enable_notifs: false
+        #   smtp_host: "localhost"
+        #   smtp_port: 25
+        """