Support SMTP without authentication

Closes #150

uffd/default_config.cfg

@@ -31,7 +31,7 @@ ACL_SIGNUP_GROUP="uffd_signup"
 
 MAIL_SERVER='' # e.g. example.com
 MAIL_PORT=465
-MAIL_USERNAME='yourId@example.com'
+MAIL_USERNAME='yourId@example.com' # set to empty string to disable authentication
 MAIL_PASSWORD='*****'
 MAIL_USE_STARTTLS=True
 MAIL_FROM_ADDRESS='foo@bar.com'

uffd/sendmail.py

@@ -24,6 +24,7 @@ def sendmail(addr, subject, template_name, **kwargs):
 		server = smtplib.SMTP(host=current_app.config['MAIL_SERVER'], port=current_app.config['MAIL_PORT'])
 		if current_app.config['MAIL_USE_STARTTLS']:
 			server.starttls()
+		if current_app.config['MAIL_USERNAME']:
 			server.login(current_app.config['MAIL_USERNAME'], current_app.config['MAIL_PASSWORD'])
 		server.send_message(msg)
 		server.quit()