Add a command to test the email config with

hedgedoc-expire.py

@@ -251,6 +251,18 @@ class HedgedocExpire:
             self.check_revisions_to_be_expired(db)
             self.check_notes_to_be_expired(db)
 
+    def cmd_emailcheck(self) -> None:
+        msg = MIMEMultipart()
+        msg['From'] = self.email_sender.mail_from
+        msg['To'] = self.email_sender.mail_from
+        msg['Subject'] = f'Hedgedoc Expire: Test Mail'
+        msg.attach(MIMEText(dedent(f'''\
+                        This is a test email to confirm proper configuration of the SMTP client.
+                        
+                        The admin team for {self.config.url}
+                        ''')))
+        self.email_sender.send(msg)
+
     def cmd_expire(self) -> None:
         with pgsql.Connection((self.config.postgres_hostname, self.config.postgres_port),
                               self.config.postgres_username, self.config.postgres_password) as db:
@@ -281,7 +293,7 @@ def main():
                         help='remove all notes not changed in these many days')
     parser.add_argument('-r', '--revisions', metavar='DAYS', type=float, default=14,
                         help='remove all revisions created more than these many days ago')
-    parser.add_argument('command', choices=['check', 'cron', 'expire'], default='check', nargs='?',
+    parser.add_argument('command', choices=['check', 'cron', 'emailcheck', 'expire'], default='check', nargs='?',
                         help='action to perform')
     parser.add_argument('-v', '--verbose', action='store_true', default=False,
                         help='print more info while running')
@@ -306,6 +318,8 @@ def main():
             if seconds > 0:
                 sleep(seconds)
             hedgedoc_expire.cmd_expire()
+    elif args.command == 'emailcheck':
+        hedgedoc_expire.cmd_emailcheck()
     elif args.command == 'expire':
         hedgedoc_expire.cmd_expire()
     else: