Bulk message sending with publish/subscribe model

We are trying to implement a notification module. It allows website internal users to send message to each other. A key feature is that it allows business users to send bulk messages to the users. We are talking about millions of users here.

Currently it is planned to be a publish/subscribe model. Once login, system shall retrieve 开发者_运维问答the relevant messages for the user from a database table. The logic gets more and more complicated when each users are allow to delete and reply to the message he/she received.

Pubsubhub seems to be more server to server. XMPP seems to be too complicated for this scenario.

Anything I miss out? Can I make it simpler? Any existing library to build on? I'm open to any suggestions.

It sounds like a database is actually all you need here. You didn't mention any need for real-time notification. If this is a web application and the user is logging in, a simple relationship between users and messages may be all you need to provide the ability to send any message to one (or millions) of users. Your relationship table can include flags for read and deleted.

One option would be to use something like Joomla.

http://www.joomla.org/

Its open source, and they've solved all the problems you are trying to solve. Alternatively if you have to build it, what language are we talking about here?

Are you seriously saying you have millions of 'internal' employees? Sounds like you might need an email server!

Seriously though, please tell us more..