I am not sur if I'm putting my quesion in the right place but I'll give it a try...
Well, I was wondering if there is a possibility to delete or modify my emails after sending them (using current protocols : SMTP, POP3 or IMAP ...).
If not, is it possible to build a new protocol than can do the job?
Thank you.
Related
I would like to implement a queuing mechanism for sending out email via PHPMailer on Amazon EC2. I have set up Beanstalkd correctly on the server and can access it via a console. The mail doesn't seem to go through (trying the various combinations of sample code). In addition do I need to set up a cron job also that would call one of the producer or consumer files?
Does anyone have working code for sending out email via phpmailer/pheanstalk please for Amazon EC2?
Thanks.
Beanstalkd is great, and I use it myself, however, don't use it for this; It's reinventing the wheel in a bad way. Instead, install a local mail server such as postfix and get that to do your queuing for you. This is also much, much simpler, faster, and easier to control. Email servers are built for managing queues, and they are extremely good at it.
Before you do so, get your mail sending script working – there's no point in even attempting to get something more complex working until you've done that. Also be aware that sending email from EC2 is difficult – Amazon wants you to use their SES service rather than sending directly – you may find sending is blocked altogether. Read the PHPMailer troubleshooting guide to see how to diagnose that.
I use django sendmail to send mail notifications through gmail.
I allways set fail_silently to false. Obviously, this a way to know if I can connect to gmail and if gmail is able to send the message, but not is enough to know if this e mail address is undeliverable.
I want to keep clean email people table. How can I do to know (by code, not by hand) If an email has been returned as undeliverable.
First of all, the bounce is an asynchronous event. In some cases it might take up to 3 days (or even more) for an undeliverable email to bounce.
In order to detect bounces, your mail server must provide support for it one or another way. Gmail doesn't do this, but you can come up with a heuristic solution using a background process that periodically scans inbox for bounces and parses them using for example imaplib. However, gmail has a sending limit which you will hit sooner or later, so I'm not sure if it's worth investing time in this solution.
Alternatively, you can use an email sending service with bounce tracking capabilities such as Postmark
I'm starting with WebSockets, I already built a chat web-application as an exercise and it went something like this:
Every user has an opened websocket connection at their arrival to the chat-room, and when new messages are available, they're simply pushed to each user. The different messages are then displayed using javaScript.
Now, I'm trying to push the exercise a bit further by creating a one-on-one chat. Basically, there will no longer be a unique chat-room but private chat conversations. A user should be able to talk to different people from the same page. (Something like Google chat or Facebook chat).
After thinking about ways to do so, I came down to two solutions:
Open multiple websocket connections. (if possible)
Use the same connection to handle all opened conversations. Basically, each message that is pushed to the client will carry a field saying to which conversation it belongs, a javaScript will then handle the display of each message under the right conversation.
To me, the second solution seems better than the first. So, my questions are:
1- Will this solution have any performance problems? (Lost messages...)
2- Is there any other-better way of doing this?
The way to go depends (IMHO) on what framework you are using to do this communication.
I (as you) would go for multiplexing (second option) where you use one connection to handle all communication.
I assume that your framework of choice supports publish/subscribe and multiplexing?
I can provide you with a simple example if you like.
Regards
Uffe, Team XSockets
I'm currently using Jetty as my websocket server and I'm trying to make a real-time game. I'm really new to this. So far I've managed to work on the easiest one (which is the chat). Now, I have a couple of issues:
I'm trying to make a list of the current users connected in the server; how do I make such feature? I don't really know if this is practical but my idea is that there's a time interval that lets the server know that "Hey, I'm still alive." I want my user list to be dynamic in such a way that if a user logs out, the list will refresh.
I'm also trying to make "rooms" for my app. Basically, the people in "Room 1" can't see what people in "Room 2" are doing; the other room functionalities are already self-explanatory. I still don't have an idea for this; can someone recommend a way to implement this?
So far I've been having fun in learning this technology, and I would be very glad if there would be incoming help. These two are my issues so far. I'm also open for any suggestions for my app.
Thank you all in advance. :-)
(Uhm, can #1 and #2 be solvable solely by Javascript?)
Your question isn't really jetty or websocket specific.
Websockets simply provide a transport mechanism for your web browser to communicate with the server - what gets set over that transport, and how the server manages information are completely separate to the websocket.
Firstly, if you haven't read it already, read this article: http://cometdaily.com/2010/03/02/is-websocket-chat-simple/
Secondly, consider using cometd to make this easier - version 2 (currently in Beta) supports websockets.
As for your questions - there are 2 things you'll need to do (cometd can help with this)
1. Define a protocol
Define a messaging protocol to sit on top of websockets. Websockets just provide a way to send chunks of data around, they don't define what that data means. You'll need to build something that does that, so you have messages that go from the client to the server like.
CONNECT "user"
STILL_ALIVE
JOIN_ROOM "room1"
LEAVE_ROOM
GET_USER_LIST
SEND_MESSAGE "message"
And then you need messages form the server to the client
RECEIVE_MESSAGE "user" "message"
RECEIVE_USER_LIST "room1"
You need to come up with some reliable way to send that data over a websocket. You can invent your own simple protocol (like the Jetty chat example does), you could use JSON, or XML, or CometD channels.
2. Server-Side State
If you've got simple chat working, then you must have made a start on this, but the other bit you need is a way to keep track of
how many users are connected
what their names are
which socket they're connected to
which room they're in
Depending on how complex your system is going to become, you might be able to just store that in 1 big singleton on the server.
I am running a web service that currently sends confirmation emails out to new users via the gmail smtp servers. As I'm only getting a few new users each day, this hasn't been a problem.
I've recently added new features to the webapp that will require a customized message to be sent out to each user every day. Think of this as similar to the regular messages LinkedIn sends out that give you a status report on the activity in your network. Every user's message will be different. With thousands of users, this means thousands of unique messages will be sent each day.
Edit: I've since found that these types of email are called "transactional or relationship messages". Spamtacular has a good article on differentiating between marketing and transactional email.
I don't think using gmail's smtp servers will cut it anymore, but I don't know that for sure. I don't know what gmail's maximum outgoing messages per account is (it might be 100/day), but they limit outgoing mail to 500 recipients per message. I'm not sending a single message to 500 recipients, but I'm going to be sending 1000's of customized messages with each recipient getting one per day.
I'm interested to learn any best practices for doing this (especially for Java-based webapps). Here are some of my thoughts and concerns on it:
Should I set up my own outgoing mail server? If I do this, it seems like I'll have all sorts of other issues to worry about, such as preventing mail server abuse, monitoring bounces, allowing ways to opt-out of emails, etc. Are there any tools or services to help with this? Maybe something like OpenEMM or a services like MailChimp? But those seem focused more toward email marketing campaigns.
I don't think I should have the webapp itself handle sending emails as it currently is for new user signups. I'm thinking I should setup a separate messaging server that can access the same backend/datastore as the webapp. Thoughts on this?
Should I consider setting up some sort of message queueing service to help with this, such as JMS, RabbitMQ, ActiveMQ, etc.?
Do I need to provide users a way to opt-out? Do I need to flag these as bulk messages? I don't really consider these email marketing messages, but I'm unsure what is considered appropriate or proper netiquette.
Any advice is appreciated. I'm also very interested in open source tools or web services that simplify things and could help me to ramp up as quickly as possible.
Thanks!
With regard to your first question, yes, you should set up your own mail server. Using gmail to do this might work for a while, but they are likely to shut you down in short order when they see this kind of activity. You could sign up for a business account and use app engine to send messages. Here's a link with information about mail quotas for that service.
Regarding your second and third questions, It would be a good idea to have messages queued by the web app and sent out by a centralized service rather than having the app send out the messages on its own.
Usually I would just use a database table as a queue - the web app inserts rows for each message it wants to send. A service/scheduled task app would grab new messages out of the table and send them off. This gives you lots of flexibility if you want to switch mail servers later, better reliability if the mail server is down, easier diagnostics if there are problems with recipients not getting messages, and the ability to resend messages. As for using JMS/MQ to do this - probably not necessary. IMO a database table used as a queue would give you more flexibility here than an actualy JMS-based queue system.
As for opt outs, YES - you should give people a way to opt out. I don't think you need to flag the messages as bulk though.
On the architecture side of things I would definitely consider decoupling the sending of the emails from the main service via some form of asynchronous message queuing (or facsimile thereof using database as an intermediary). Another benefit of this approach is that if the SMPT server\network is down you could build in retry semantics, additionally for future scalability you could implement multiple mail senders reading from the same queue or implement sending throttling or scheduling (i.e send n messages per hour), etc etc.